FLASH: https://bbb1.physnet.uni-hamburg.de/b/ale-jmp-azf-rm4
PETRA III: https://bbb1.physnet.uni-hamburg.de/b/mel-k00-0vj-tu6
ALPS: https://bbb1.physnet.uni-hamburg.de/b/ale-kxw-u3u-vnf
Sternwarte Bergedorf: https://bbb1.physnet.uni-hamburg.de/b/ale-ddd-oij-qge
XFEL: https://bbb1.physnet.uni-hamburg.de/b/mel-aet-2im-b6m
ZOQ: https://bbb1.physnet.uni-hamburg.de/b/ale-heq-tz2-7ut
Virtuelle Labortour durch die HERA-Tunnel West: Mittels optischer Technologien der Gravitationswellendetektoren sollen mit dem Hochpräzision-Experiment „ALPSII" Axion-ähnliche Teilchen am DESY nachgewiesen werden.
https://bbb1.physnet.uni-hamburg.de/b/ale-kxw-u3u-vnf
Join a virtual tour of the world's first X-ray free-electron laser FLASH.
https://bbb1.physnet.uni-hamburg.de/b/ale-jmp-azf-rm4
Virtueller Rundgang durch die Hamburger Sternenwarte. Am Anfang der Tour wird entschieden, ob sie auf englisch oder deutsch ist.
Virtual tour through the hamburg observatory. At the beginning of the tour it is decided whether it is in English or German.
https://bbb1.physnet.uni-hamburg.de/b/ale-ddd-oij-qge
Join a virtual tour of the world's most brilliant storage ring X-ray source PETRA III, located at DESY.
https://bbb1.physnet.uni-hamburg.de/b/mel-k00-0vj-tu6
Join a virtual tour of the largest X-ray laser in the world.
https://bbb1.physnet.uni-hamburg.de/b/mel-aet-2im-b6m
Join a virtual tour through laser labs of the Centre for Optical Quantum Technologies.
https://bbb1.physnet.uni-hamburg.de/b/ale-heq-tz2-7ut
https://bbb1.physnet.uni-hamburg.de/b/ale-qpi-sr5-7ij
In August 2017, the first detection of a neutron star merger, GW170817, created an opportunity to explore the equation of state of supranuclear matter using gravitational waves. But it is unknown under what circumstances this kind of gravitational wave data could distinguish between different types of mergers. For example, can the data distinguish a merger of black holes from a merger of neutron stars or the merger of a neutron star and a black hole? Here we build on earlier results using chiral effective field theory to explore whether the data from LIGO and Virgo, A+, Voyager, or Cosmic Explorer can lead to such a distinction. The results suggest that LIGO and Virgo will be able to distinguish between a binary neutron star and a binary black hole but not between neutron-star--black-hole binary and a black hole binary.
Typical neutron stars have a mass of the order of a solar mass and a radius of about 10 km, making them the most compact objects in our universe. However, the extreme conditions inside a neutron star, i.e., an extremely high density, cannot be reproduced on Earth. Therefore, the equation of state describing extremely compact nuclear matter is still largely unknown. Due to their small size and the fact that they emit almost no significant electromagnetic radiation, neutron stars are very difficult to observe. Since their first detection in August 2017, it is now possible to study them with the help of gravitational waves, which have been emitted millions of years ago during the merger of two inspiraling neutron stars. This was the first event ever that was detected both in the electromagnetic and the gravitational wave spectrum, heralding the beginning of the so-called multimessenger astronomy. My own research focuses on oscillations of hot, massive neutron stars that are possible remnants of a binary neutron star merger. During the violent formation, certain oscillation modes are excited and emit copious amounts of gravitational waves which, if detected, will provide valuable information about the stellar composition.
Axions are well-motivated theoretical particles that are also dark matter candidates. They can form enormous clouds around black holes, and then annihilate to produce a long-lived, slowly-evolving continuous gravitational-wave signal. This signal is potentially detectable using the current generation of gravitational-wave interferometers, and a non-detection can disfavor the existence of axions in certain mass ranges. I will discuss the expected gravitational-wave signal from axion clouds around the black holes in the Galaxy, and the prospects for detecting the signal using standard searches for continuous gravitational waves.
https://bbb1.physnet.uni-hamburg.de/b/ale-fr7-chs-oac
The Belle II experiment, located at the SuperKEKB $e^+ e^-$- collider in Japan, uses pulse shape analysis techniques to distinguish electromagnetically and hadronically interacting particles within the CsI(Tl) electromagnetic calorimeter. The waveforms from the particle dependent scintillation response within the CsI(Tl) scintillators are analyzed with a multi-template offline fit. This fitting method allows to determine the total deposited energy, the deposited hadron energy and the time of energy deposit. This presentation reports on an alternative method to extract the total deposited energy and the deposited hadron energy from the waveforms using machine learning techniques. For this a neural network is trained on simulated $\gamma$- and $\pi^{\pm}$-data and is employed as a multivariate regression tool. I will show the comparison between the performance of the neural network and the performance of the current fitting method. The neural network shows an improvement in its total and hadron energy resolution and high robustness towards waveform fluctuations.
Our main objective is to measure the total cross-section for inclusive charm production at different proton-proton center of mass energies (0.9, 2.7, 5, 7, 8, and 13 TeV). We measure the charm cross-section through the decays of D mesons. For the 7 TeV analysis, we are using CMS Open Data.
CMS Open Data is data taken by the CMS experiment released to the public via the CERN Open Data portal (http://opendata.web.cern.ch). The purpose is to encourage the public or external researchers to conduct their analyses using the original preserved data. CMS Open Data can be used not only for research but also for educational purposes.
One example using CMS Open Data that has been made public is the Higgs to 4 lepton analysis. This simplified analysis rebuilds part of the historic Higgs discovery based on original CMS datasets.
In this talk, a measurement of the total charm cross-section at 7 TeV and a simplified Higgs to 4 leptons analysis using the CMS Open Data will be presented.
One of the main goals of LHC experiments is the precise measurement of the Higgs boson's production properties in order to clarify its coupling structure. In Standard Model physics the coupling of the Higgs boson to fermions are introduced as Yukawa couplings. Due to the high branching ratio of the Higgs boson decay into tau leptons and the lower background contribution compared to $H\rightarrow b\bar{b}$ , the $H\rightarrow\tau\tau$ channel is an interesting channel to probe the Higgs coupling to fermions.
The presented measurement is performed using data collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2018 corresponding to an integrated luminosity of 59.7 fb$^{-1}$.
The analysis is based on a multi-class neural network, which classifies the events into two signal classes (gluon-gluon and vector boson fusion production) and several background classes.The e$\mu$ final state of the tau lepton pair is studied.
The main challenge in the analysis is the differentiation between the signal events produced via gluon-gluon fusion and the irreducible background process where a Z boson decays into tau lepton pair.
In this talk, studies aiming to improve the separation power of the neural network between these processes will be presented.
https://uni-hamburg.zoom.us/j/99156607156?pwd=RHVLeUloMlc3QXUzWnZHN1lHRm1lUT09
Meeting-ID: 991 5660 7156
Die Bereitschaft mikropolitisch zu handeln wirkt sich positiv auf die Realisierung von (Karriere-)Zielen aus. Hinter dem Begriff Mikropolitik verbergen sich die kleinen, unsichtbaren Spiele der Macht, die sich auf der Hinterbühne abspielen. Sich mikropolitische Kompetenz anzueignen, eröffnet die Chance das eigene Machtpotenzial zu entdecken und dieses für die Realisierung von beruflichen Zielen erfolgreich einzusetzen. Dem stehen jedoch Hindernisse entgegen. Zu den wirkungsvollsten zählen Handlungsblockaden, die auf verinnerlichte Geschlechterstereotype und Geschlechtersozialisation beruhen. Der Anspruch von Perfektion und einer Karriere, die hauptsächlich auf Leistung basiert, wirkt sich nicht nur negativ auf die eigene Work-Life-Balance aus, sondern führt dazu, dass die Bedeutsamkeit von Networking durch z. B. die Mitwirkung in Gremien für die Realisierung von Karrierezielen unterschätzt wird.
Um das eigene mikropolitische Potenzial voll zu entfalten und es für die Gestaltung der Karriere produktiv einzusetzen, gilt es (diese und weitere) mächtige Handlungsblockaden zu erkennen und sich Wissen über die Erweiterung von Handlungsspielräumen anzueignen.
Doris Cornils geht in ihrem Vortrag auf Potenziale und Hindernisse beim Aufstieg im MINT-Bereich ein. Sie lädt die Zuhörer*innen ein gemeinsam die “mikropolitische Brille” aufzusetzen und die Aufstiegsspiele aus gendersensibler Perspektive zu reflektieren.
Es handelt sich um einen 60-minütigen Fachvortrag. Anschließend besteht für 30 Minuten die Möglichkeit Fragen an die Referentin zu stellen und in den Austausch zu gehen.
https://bbb1.physnet.uni-hamburg.de/b/ale-5rh-xyl-spp
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
The Large Hadron Collider LHC at CERN is the biggest scientific instrument constructed by mankind until today which allowed for the discovery of the Higgs boson in 2012After the European Strategy of particle physics has presented its conclusions this year, what are the next challenges for particle physics?
More than 10000 scientists from all over the world use this exceptional research infrastructure to unveil the infinitely small and to understand the fundamental laws of our Universe. What is the personal motivation to do research in particle physics? And the experience to work in this field between daily tasks and big questions?
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
Ein Empfang im Hamburger Rathaus… das waren Anfang des Jahres unsere Pläne für den ersten Abend der Physikinnentagung 2020. Mit der Covid-19-Pandemie hieß es umdenken, in so vielen Bereichen. Dennoch wollen wir nicht auf eines der Herzstücke der Physikinnentagung verzichten: die Chance zum Netzwerken und die Möglichkeit zu einem weitreichenden und ausführlichen Austausch. Die Abendveranstaltungen einer Konferenz sind dafür typischerweise die ideale Gelegenheit und diese wollen wir Euch auch dieses Jahr bieten, online.
Beim Get-together Online Dinner werden wir Euch zunächst die Möglichkeit geben, andere Teilnehmende besser kennenzulernen. Danach wird es verschiedene Breakout Rooms geben, in denen Ihr die Möglichkeit habt Gespräche weiter zu vertiefen.
Eines ist uns dabei wichtig: Dies ist der gemütliche Teil des Abends! Wir freuen uns, wenn Ihr es Euch dabei mit einem Getränk und einem Snack vor dem PC gemütlich macht. Krümeln ist ausdrücklich erlaubt!
A reception in Hamburg's town hall ... those were our plans for the first evening of the Women Physicists' Conference 2020 at the beginning of the year. With the Covid-19 pandemic, we had to rethink in so many areas. Nevertheless, we do not want to do the Women Physicists' Conference 2020 without one of the core elements: the chance to network and the opportunity for a far-reaching and detailed exchange. The evening events of a conference are typically the ideal opportunities for this and we want to offer them to you this year as well, online.
At the get-together online dinner we will first give you the opportunity to get to know other participants better. Afterwards there will be various breakout rooms in which you have the opportunity to deepen discussions.
One thing is important to us: This is the cozy part of the evening! We would appreciate it if you could make yourself comfortable with a drink and a snack in front of the PC. Crumbling is expressly allowed!
https://bbb1.physnet.uni-hamburg.de/b/ale-hic-ufi-ltu
Das Forschungszentrum Jülich leistet wirksame Beiträge zur Lösung großer gesellschaftlicher Herausforderungen in den Bereichen Information, Energie und Bioökonomie. Dabei kommt dem Fachgebiet der Physik eine ganz besondere Bedeutung zu - über 900 Personen mit einem Hintergrund in Physik arbeiten aktuell am Forschungszentrum. Im Vortrag erfahren Sie, welchen Themen und Fragestellungen sich das Forschungszentrum Jülich widmet, was das Arbeiten und Forschen ausmacht, welche Karrieremöglichkeiten sich Ihnen bieten und wie wir unsere Mitarbeitenden bei der Vereinbarkeit von Beruf und Familie unterstützen.
· Alissa Aarts studierte Betriebswirtschaft mit den Schwerpunkten Personal und Marketing und ist seit 2015 im Forschungszentrum Jülich tätig. Im Recruiting unterstützt sie verschiedene wissenschaftliche Institute bei der Personalauswahl und steht darüber hinaus durch unterschiedliche Aktivitäten im nationalen und internationalen Personalmarketing stets mit interessierten Kandidatinnen und Kandidaten in Kontakt.
· Sabrina Schwarz machte am Forschungszentrum Jülich zunächst eine Ausbildung zur Physiklaborantin und arbeitete im Anschluss zwei Jahre im Institut für Bio- und Geowissenschaften. Mit ihrem Studium der Sozialwissenschaft (Bachelor) und Soziologie (Master) hat sie einen beruflichen Richtungswechsel vollzogen und parallel eine Tätigkeit im Büro für Chancengleichheit am Forschungszentrum begonnen. Dort befasst sie sich heute als Referentin für Chancengerechtigkeit mit Vereinbarkeitsthemen und der Förderung von Frauen in der Wissenschaft.
https://bbb1.physnet.uni-hamburg.de/b/ale-hic-ufi-ltu
Infineon entwirft, entwickelt, fertigt und vertreibt eine Vielzahl an Halbleiter- und Systemlösungen. Dabei liegt der Fokus auf der Automobil- und Industrieelektronik sowie auf mobilen Geräten, Hochfrequenzanwendungen und hardwarebasierter Sicherheit. Komponenten von Infineon kommen zum Einsatz, wo elektrische Energie effizient erzeugt, übertragen und genutzt wird. Sie sichern ferner unseren digitalen Datenaustausch, senken den Schadstoffausstoß von Autos und erhöhen die Sicherheit im Straßenverkehr. So macht Infineon den Alltag einfacher, sicherer und umweltfreundlicher.
Halbleitertechnologie basiert maßgeblich auf physikalischen Grundlagen. Deshalb überrascht es nicht, dass rund ein Viertel der Infineonmitarbeiter*innen mit akademischem Abschluss Physik studiert haben – viele davon mit Promotion.
Natascha Dinkelacker studierte Physik an der Universität Bonn und dem Karlsruher Institut für Technologie. Im Anschluss promovierte sie im Bereich der Detektorentwicklung für das CERN, die Europäische Organisation für Kernforschung, am Max Planck Institut für Physik und der Ludwig Maximilian Universität in München. Seit 2018 ist sie als Produktions- und Projektmanagerin bei Infineon tätig. Als Produktionsmanagerin ist sie zuständig für eine stabil laufende Produktion von neu auf den Automobil-Markt gebrachten Sensoren, die zuvor bei Infineon in-house entwickelt worden sind. Als Projektmanagerin hat sie die Verantwortung, Projekte mit interdisziplinarischen Teams über unterschiedliche Infineon-Standorte hinweg gemäß Projektumfang, Zeitlplan und Budget zu leiten. - Im Vortrag erfahren Sie, wie Natascha Dinkelacker der Wechsel von der Wissenschaft in die Industrie gelungen ist und was dabei wichtig war. Außerdem geht sie darauf ein, wie sie als Physikerin die Firmenkultur bei Infineon in Bezug auf Innovation, Vereinbarkeit von Beruf und Privatleben und persönlicher Weiterentwicklung erlebt.
https://bbb1.physnet.uni-hamburg.de/b/ale-hic-ufi-ltu
Messer wurde 1898 gegründet und ist heute der weltweit größte familiengeführte Spezialist für Industrie-, Medizin- und Spezialgase. Unter der Marke ‚Messer – Gases for Life‘ werden Produkte und Gasetechnologien in Europa, Asien und Amerika angeboten. Stefan Messer, Eigentümer und CEO der Messer Group GmbH, arbeitet zusammen mit weltweit rund 11.000 Mitarbeitenden nach definierten Prinzipien: Dazu gehören Kunden- und Mitarbeiterorientierung, verantwortliches Handeln, unternehmerische Verantwortung, Exzellenz sowie Vertrauen und Respekt.
Informationen zur Messer Group - Gases for Life:https://www.youtube.com/watch?v=H_1IRhcelSA
Der erste Film demonstriert ganz schön, was wir bei Messer so machen, wie die Gase erzeugt werden, wofür man sie braucht usw.
Für die Physikerinnen sicherlich der interessantere Film. Der zweite Film ist unser Imagefilm:
https://www.youtube.com/watch?v=x-evdfITOtk
Fragen gerne an Marlen Schäfer stellen: Marlen.Schaefer@messergroup.com
https://bbb1.physnet.uni-hamburg.de/b/ale-0y5-gms-zzf
Galaxy clusters exhibit spectacular elongated radio emission in their outskirts called radio relics. Recent high-resolution radio observations of radio relics reveal us new substructure and features. While this is a clear signature of cluster magnetic fields, the underlying plasma properties in these cluster regions remain unclear. In this work, we present results from three-dimensional magneto-hydrodynamical simulations of shocks propagating through a turbulent intracluster medium. We model the synchrotron emission coming from cosmic-ray electrons by assuming the diffusive shock acceleration mechanism. We study the role of turbulence in shaping the substructure of radio relics. We will discuss the impact on the observational counterpart and its relevance for studying magnetic fields in galaxy clusters outskirts.
Synthetic spectra from model atmospheres are frequently used in the analysis of observed spectroscopic and photometric data. For the most part, the models are sufficiently detailed to test the current theoretical understanding of stellar and sub-stellar mass objects at various stages in their evolution. However, the vast majority of model atmospheres are constructed under the assumption that the nearest stellar neighbor is so far away that it can be safely ignored. This assumption, while safe for most stars, fails for many short period binaries. A number of binary systems have orbital separations small enough so that one of the binary members is significantly heated by its companion. In order for synthetic spectra to be useful in such cases, the standard “isolated” modeling approach must be replaced by one that includes the effects of irradiation.
The AADor system is an excellent example of a well-studied close binary system. Its members are a hot subdwarf and an extremely low mass cool companion. I will present you how several PHOENIX/1D models combined to a 1.5D model can represent this system and compare these results to a PHOENIX/3D model that is able to include 3D effects like transverse radiation and transmission of light close to the terminator.
CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) is a direct dark matter search experiment, located at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, where an overburden of 1400m of rock (3800m water equivalent) provides an efficient reduction of the cosmic radiation background.
In the CRESST experiment, ~25g scintillating $\mathrm{CaWO_4}$ crystals are used as target material for elastic DM-nucleus scattering and operated as cryogenic detectors. An intrinsic radioactive contamination of the crystals and surrounding materials of as low as possible is crucial for the sensitivity of the experiment. Since 2011 $\mathrm{CaWO_4}$ crystals are grown at the crystal laboratory of the Technische Universität München (TUM) to better meet the requirements of the CRESST experiment. The new generation of TUM-grown crystals are grown using recrystallization and low speed growing.
Furthermore, an extensive screening campaign is going on to study the level of contamination in parts of the setup. Its results can be used as an input for the simulation of the background of the CRESST experiment.
Line Intensity Mapping (LIM) targets the Universe from present time up to redshifts beyond ten when the first galaxies formed, from small to largest scales. Similar to CMB measurements, power spectra of emission line fluctuations tell both about structure growth and underlying cosmology as well as astrophysical processes. Imagine the information encoded in thousands of intensity maps at different redshifts and for multiple emission lines.
In this talk I will review LIM as a test for cosmology and astrophysics during the dark ages and the epoch of reionization, with power, cross-power spectra and global temperature signals probing structure formation and properties of astrophysical sources. As examples 1) cosmological volumes of 21cm fluctuations and their global temperature signal in general modified gravity scenarios are highlighted to measure deviations from the gravitational constant G and a possible dark matter -- dark energy coupling, 2) synergies for probing astrophysics with Lyman-alpha and H-alpha lines are explored.
In this talk, I will discuss black hole solutions that evade the famous "No hair"
theorem and carry - next to mass and charge - additional features on their
horizon in the form of scalar fields. Interestingly, when considering the strong gravity regime, these black holes look as if they were inflating. This leaves the possible
interpretation of a black hole having formed in the early universe that has expanded
to large sizes during the inflationary epoch.
Understanding its origins is one of humanity oldest and most recurrent aspiration. In the latest centuries, physics has enabled us to push further and further this quest for the origins of our universe, resulting in the mid-20th century in the famous theory of the Big Bang and, later, that of inflation.
The Big Bang theory is based on the description of gravitational interaction by General Relativity and is in astonishing concordance with all experimental data collected so far. Nevertheless, there are still huge gaps in our understanding of early phases of the universe. The theory of inflation was one attempt to fill some of these gaps, but it is only partially successful. For example, inflation is quantum incomplete, which means it must still be supplemented by a theory of initial conditions of the universe. Moreover, it has been known for decades that General Relativity is not compatible with quantum theory. But describing the very beginning of the universe would precisely require those two theories to merge in what would be a theory of quantum gravity.
The no-boundary proposal is a theory of the initial conditions of the universe, i.e. it is precisely describing the early quantum phase that would have taken place before the inflationary phase. It is formulated in semi-classical gravity, i.e. a first approximation to quantum gravity in the limit where we recover a classical behaviour. It relies on the existence of regular solutions of the equations of motions and has been recently put on firm theoretical grounds within the framework of General Relativity. Since we know General Relativity is not the end of the story, it is crucial to know whether this no-boundary proposal will still be a solution to the equations of motion for theories involving quantum corrections to General Relativity. Even if we don’t know the form of this would-be Quantum Gravity, we can already try to see how the no-boundary proposal applies to several candidates like string theory.
In our work we have shown by explicit computation that regular no-boundary solutions are modified, but not destroyed, upon inclusion of expected quantum gravity corrections and illustrated our results with examples drawn from string theory. These calculations provide a crucial self-consistency test of the no-boundary framework.
https://uni-hamburg.zoom.us/j/99674902762?pwd=UjVHVStxa1BuVDM5VEdFUE1VcUVEZz09
Meeting-ID: 996 7490 2762
Zoom-Meeting beitreten
https://uni-hamburg.zoom.us/j/98463136483?pwd=TDdxN053Y2RnUzZteTRKS0g5bU15Zz09
Meeting-ID: 984 6313 6483
https://bbb1.physnet.uni-hamburg.de/b/ale-x50-tqn-0jq
https://bbb1.physnet.uni-hamburg.de/b/ale-bvw-2tw-opj
Mixed-valence manganites are very promising candidate materials for resistive-switching devices due to the possibility to generate multilevel resistance states as well as area-dependent switching. This enables their use in future non-volatile memories or novel neuromorphic circuits.
The aim of our work is to gain a deeper understanding of the microscopic mechanisms of resistive switching in mixed valence manganites with the focus on Sr-doped LaMnO3 (La1-xSrxMnO3±δ, LSMO). It is widely accepted that ionic transport, especially oxide-ion transport, plays an important role in the field of resistive switching. Nevertheless, the role played by dislocations (one dimensional lattice defects) in the switching process is unknown. LSMO is unusual amongst the perovskite oxides, since it is the only system to show fast diffusion of oxygen along dislocations. The reasons for this behaviour are however not understood.
To this end, we studied the ionic transport in bulk LSMO as well as along low-tilt grain boundaries (that consist of a periodic array of dislocation) by Molecular Dynamics simulations, employing empirical pair potentials. In particular, the effect of Sr dopants and cation vacancies on oxide-ion transport is examined.
Research on amorphous oxide semiconductors (AOS) has developed rapidly over the last two decades driven by the search for thin-film transistor channel materials suitable for the backplanes of high-definition active matrix displays with organic light-emitting diodes (AMOLED) and for performance optimization of low-cost sensing networks (e.g. RFID-chips) that can be incorporated into smart clothing. AOS materials show remarkable electrical transport properties despite their disordered structure. In contrast to polycrystalline materials the charge carrier transport in AOS is not limited by grain boundary scattering and occurs via delocalized s-orbital states above the mobility edge.[1] The amorphous multi-cation compound zinc tin oxide (a-ZTO) and the amorphous multi-anion compound zinc oxynitride (a-ZnON) with electron Hall mobilities of $13\, \text{cm}^2\text{V}^{-1}\text{s}^{-1}$ [2] or up to $100\, \text{cm}^2\text{V}^{-1}\text{s}^{-1}$ [3,4] have been proven to be possible indium-free alternatives to amorphous indium gallium zinc oxide (a-IGZO) for pixel drivers in active matix displays.
In this talk results on a-ZnON with magnesium cation substitution and its effect on the optical and electrical properties are presented. Furthermore, a short insight into the percolative charge carrier transport mechanism and an overview covering the latest device applications based on a-ZnON, a-ZnMgON and a-ZTO as pn-diodes and metal-semiconductor field-effect transistors (MESFETs)[5] is given.
[1] H. Hosono et al., J. Non-Cryst. Solids 352, 851 (2006)
[2] P. Schlupp et al., MRS Proceedings 1633, 101-104 (2014)
[3] A. Reinhardt et al., Phys. Status Solidi A 213 (7), 1767 (2016)
[4] H. Kim et al., Sci. Rep. 3, 1459 (2013) \newline
[5] A. Reinhardt et al., Adv. Electron. Mater 6, 1901066 (2020)
Humanity is faced with many global challenges, two crucial challenges are climate change and the growing demand for energy, especially in previously underserved regions of the world. One technology that helps address both of these challenges are photovoltaic solar cells. To speed up the widespread utilization of photovoltaics (PV) the efficiency of solar cells needs to rise further while the price needs to continue to decrease. The current industry standard are silicon solar cells. These are an established technology which reaches power conversion efficiencies (PCEs) of up to 27% and has seen a remarkable drop in retail price over the last five years. Silicon solar cells are reaching a limit and future improvements will be hard to come by. A promising new type of solar cells is based on hybrid organic-inorganic perovskite materials. These have attracted a lot of research interest as they are a highly promising and versatile group of materials. On the lab scale perovskite solar cells have reached record efficiencies of 25.3% on their own and 29.1% in a tandem solar cell together with silicon. Perovskite materials can be processed with much less energy input than silicon and can be integrated into flexible solar cells as well as applications beyond PV including LEDs and transistors. This makes them a highly interesting group of semiconductors which could form the basis for the next generation of solar cells and other optoelectronic devices. My research focuses on the fabrication, characterisation and optimisation of perovskite thin-films via co-evaporation in vacuum. Co-evaporation is a promising techniques as it is solvent free, fully additive, scalable and offers a high degree of control over the thickness and composition of the film. I will particularly focus on novel materials realised with co-evaporation [1] and the influence of impurities on the deposition process [2].
[1] Borchert, J., Milot, R. L., Patel, J. B., Davies, C. L., Wright, A. D., Martínez Maestro, L., … Johnston, M. B. (2017). Large-Area, Highly Uniform Evaporated Formamidinium Lead Triiodide Thin Films for Solar Cells. ACS Energy Letters, 2(12), 2799–2804. https://doi.org/10.1021/acsenergylett.7b00967
[2] Borchert, J., Levchuk, I., Snoek, L. C., Rothmann, M. U., Haver, R., Snaith, H. J., … Johnston, M. B. (2019). Impurity Tracking Enables Enhanced Control and Reproducibility of Hybrid Perovskite Vapor Deposition. ACS Applied Materials & Interfaces, 11(32), 28851–28857. https://doi.org/10.1021/acsami.9b07619
My work is focussed on one of the most compelling unconventional superconductors to date, Strontium Ruthenate ($Sr_2RuO_4$). It has become a benchmark for experimentation and theoretical analysis because its normal-state electronic structure is known with exceptional precision, and because of experimental evidence that its superconductivity breaks time-reversal symmetry (TRS)i.e. chiral. Measurements under uniaxial strain offer an ideal way to test for chirality because under uniaxial strain the superconducting and chiral transitions are predicted to split, allowing the empirical signatures of each to be identified separately.
By combining Muon spin relaxation (which is a unique tool to study structural and dynamical processes that are taking place in the bulk of a material in an atomic scale) and the application of uniaxial strain (which is a good way to perturb a material without introducing any disorder) I am searching for conclusive evidence regarding the superconducting order parameter of $Sr_2RuO_4$. For this purpose, we developed a uniaxial strain device1 that is expected to widen the range of applications of the Muon spin relaxation method. Using this device, we observed a large strain-induced splitting between the onset temperatures of superconductivity and TRSB in $Sr_2RuO_4$. Moreover, at high strain beyond the van Hove singularity, a new spin density wave ordered phase is observed2.
[1 ] C. Hicks et al. Piezoelectric-Driven Uniaxial Stress Apparatus for Muon Spin Rotation. JPS Conf. Proc. 21, 011040 (2018)
[2 ]V. Grinenko, S. Ghosh et al, Split superconducting and time-reversal symmetry-breaking transitions and magnetic order in $Sr_2RuO_4$ under uniaxial stress. arXiv:2001.08152
By virtue of its inherent two-dimensional (2D) nature van der Waals (vW) materials offer a robust and easily realizable platform for future technological applications. Superconductivity is one among the various quantum phenomena that these systems have exhibited. Among vW systems NbSe2 is inherently superconducting and semiconducting systems such as MoS2, WSe2 etc has shown superconductivity when increasing the carrier concentration. One of the polymorphic phases of MoS2, the metallic 1T phase also showed superconductivity. Electrical characterization on the few-layer 1T MoS2 sample owing to its high carrier density also reveals transition to a 2D superconducting phase with characteristic Berezinskii–Kosterlitz–Thouless transition (BKT) phase transition and anisotropy in the magneto-transport with respect to field directions below 1 K. The features of superconductivity in 2D will be discussed stressing on 1T MoS2. Interesting features such as Ising superconductivity and Bose metal phase observed in some of these systems will also be touched upon.
In this talk, a set of virial relations for many electron systems coupled to both classical and quantum fields will be presented [1]. The setting for which these relations hold is the Pauli–Fierz Hamiltonian . Recently, there is growing interest in solutions of this Hamiltonian due to its relevance for describing molecular systems strongly coupled to photonic modes in cavities, and in the possible modification of chemical properties of such systems compared to the ones in free space.
[1] Virial relations for electrons coupled to quantum field modes
Iris Theophilou, Markus Penz, Michael Ruggenthaler, and Angel Rubio
J. Chem. Theory Comput. 2020 https://doi.org/10.1021/acs.jctc.0c00618
https://bbb1.physnet.uni-hamburg.de/b/ale-fea-q71-rtn
The German Research Foundation (DFG) is Germany’s largest funding organization. The evaluation and funding of research projects is one of the core tasks of the DFG, the other are the promotion of early career researchers and the promotion of equal opportunities. Recently, all funding programs have been reexamined for possible structural obstacles. The resulting measures will be discussed. As part of this equal opportunity concept, a strong focus is to avoid implicit bias in the review process and funding decisions. Implicit bias refers to stereotypes that affect actions and decisions in an unconscious manner. The challenge is to recognize these stereotypes and develop mitigating strategies. This talk will explore examples of stereotypes in physics and implicit biases within decision processes.
https://uni-hamburg.zoom.us/j/99071209448?pwd=amtlblRkb0dtL3lXckcxU3NwUnllZz09
Meeting-ID: 990 7120 9448
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
In Physikvorlesungen und Physiklehrbüchern wird physikalisches Fachwissen vermittelt und zum Teil an Experimenten demonstriert. Darüber hinaus werden den Lernenden aber gleichzeitig meist unbewusst und oft sogar unausgesprochen zahlreiche Erzählungen, sogenannte Narrationen der Physik, vermittelt. Diese Narrationen handeln davon, wer von den Neulingen für ein Physikstudium geeignet ist und wer nicht, wer die Helden des Feldes sind, die aus ihrem genialen Geist die heutige Physik entwickelt haben, welche Werte und Verhaltensweisen in der Physikcommunity „normal“ sind oder welche Eigenschaften es braucht, um sich erfolgreich an der Weiterentwicklung der Physik beteiligt zu können.
Mit einem kulturwissenschaftlichen Blick auf Physiklehre in Vorlesungen und Lehrbüchern, wie ihn z.B. die Geschlechterforschung zur Physik einnimmt, können diese „heimlichen“ Narrationen sichtbar und ihre Ausschlüsse hinterfragbar gemacht werden. In der Veranstaltungen werden anhand von konkreten Forschungsbeispielen und eigener Lehrerfahrung einige dieser Narrationen vorgestellt. Anschließend werden Lösungen vorgestellt, wie Erzählungen über Physik vielfältiger gestaltet werden und Physiklehrende damit selbst zur Erhöhung der Attraktivität der Physik beitragen können. Dabei wird auch die Frage diskutiert, ob und wie Digitalisierung zu einem Verfestigen oder Aufbrechen traditioneller Vorstellungen einer „männlichen, weißen Physik“ beiträgt bzw. sinnvoll genutzt werden kann.
Prof. Dr. Helene Götschel
TU Darmstadt, Institut für Allgemeine Pädagogik und Berufspädagogik
Helene Götschel, Physikerin (Dipl.-Phys.), Historikerin (Dr. Phil.), Hochschuldidaktikerin und Geschlechterforscherin, ist Gastprofessorin am Institut für Allgemeine Pädagogik und Berufspädagogik an der TU Darmstadt mit dem Arbeitsschwerpunkt Pädagogik der Naturwissenschaften. Davor hat sie 5 Jahre lang als Maria-Goeppert-Mayer Professorin für Gender und Diversity Physikvorlesungen an der Fakultät für Maschinenbau der Hochschule Hannover durchgeführt und zu der Frage geforscht, wie Physik ansprechend für Alle gelehrt werden kann.
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
Die COVID-19-Pandemie hat die Welt verändert und somit das Leben jedes einzelnen Menschen. In Deutschland ist der Verlauf der Pandemie vergleichsweise mild.
Trotzdem spüren wir die Einschränkungen in vielen Lebensbereichen. So hat sich auch das Lernen und Lehren an Universitäten, Fachhochschulen und
Forschungseinrichtungen im Jahr 2020 stark geändert: Das Homeoffice ist der Regelarbeitsplatz, Laborarbeiten finden nur unter strengen Hygienevorschriften statt, die Kommunikation mit Kolleginnen
geschieht nicht mehr persönlich, Vorlesungen finden zu Hause digital statt und nebenbei müssen viele Wissenschaftlerinnen/Studentinnen für Angehörige Besorgungen erledigen und/oder die Kinderbetreuung zu Hause alleine stemmen.
Mit unserer Diskussionsrunde möchten wir einen Raum bieten in dem sich alle Interessierten bezüglich ihrer Erfahrungen austauschen können. Was läuft gut im Homeoffice? Was läuft überhaupt nicht?
Was wünschen sich die Studentinnen von den Lehrenden an den Hochschulen und umgekehrt? Wie können wir den digitalen Betrieb an Hochschulen verbessern? Wir freuen uns auf den regen Austausch und
hoffen gemeinsam Lösungsansätze für aktuelle Probleme entwickeln zu können.
https://bbb1.physnet.uni-hamburg.de/b/mel-7sc-0at-kmy
Der Arbeitskreis Chancengleichheit (AKC) der DPG lädt herzlich zur jährlichen Mitgliederversammlung ein. Die AKC-Kommission berichtet über die Arbeit des vergangenen Jahres und gibt eine Vorschau über geplante Projekte und Veranstaltungen. In einer offenen Diskussionsrunde können alle Anwesenden eigene Ideen und Anregungen in die AKC-Arbeit einbringen. Alle Interessierten sind jederzeit herzlich eingeladen, sich aktiv an Projekten zu beteiligen. In diesem Jahr findet Coronabedingt keine Wahl statt. Dies ist vereinbar mit den DPG-Vorgaben. Trotzdem möchten wir alle Mitglieder gerne dazu auffordern, die AKC-Kommission zu unterstützen und bei diversen Themen mitzuarbeiten. Wir haben viel zu tun und freuen uns über jede Art von Unterstützung.
Die AKC-Komission freut sich auf eine zahlreiche Teilnahme.
Der Arbeitskreis Chancengleichheit (AKC) der DPG lädt herzlich zur jährlichen Mitgliederversammlung ein. Die AKC-Kommission berichtet über die Arbeit des vergangenen Jahres und gibt eine Vorschau über geplante Projekte und Veranstaltungen. In einer offenen Diskussionsrunde können alle Anwesenden eigene Ideen und Anregungen in die AKC-Arbeit einbringen. Alle Interessierten sind jederzeit herzlich eingeladen, sich aktiv an Projekten zu beteiligen. In diesem Jahr findet Coronabedingt keine Wahl statt. Dies ist vereinbar mit den DPG-Vorgaben. Trotzdem möchten wir alle Mitglieder gerne dazu auffordern, die AKC-Kommission zu unterstützen und bei diversen Themen mitzuarbeiten. Wir haben viel zu tun und freuen uns über jede Art von Unterstützung.
Die AKC-Komission freut sich auf eine zahlreiche Teilnahme.
https://bbb1.physnet.uni-hamburg.de/b/mel-pfx-pau-34j
https://bbb1.physnet.uni-hamburg.de/b/mel-b0s-bnl-7zp
https://bbb1.physnet.uni-hamburg.de/b/ale-1gt-ghb-rrk
Diskussionsrunde mit Katharina Menne, Wissenschaftsjournalistin der ZEIT
https://bbb1.physnet.uni-hamburg.de/b/ale-1gt-ghb-rrk
Discussion with Sarah Anne Aretz, DESY Science Communication.
Wissenschaftskommunikation wird mehr denn je groß geschrieben. Doch was braucht es eigentlich für eine gelungene Kommunikation hinter der Kommunikation von Wissenschaft in die Öffentlichkeit? In dieser Kaffeepause tauschen wir uns aus über Erfahrungen an der Schnittstelle zwischen Forschenden und Kommunikationsverantwortlichen. Was läuft gut, was könnte besser sein und welche Veränderungen hat die aktuelle Pandemie gebracht?
Diskussionsrunde mit Anna Walter, Wissenschaftsredaktion des Exzellenzcluster Quantum Universe.
https://bbb1.physnet.uni-hamburg.de/b/ale-1gt-ghb-rrk
Diskutiert mit Diana Haas und Kim Plath vom DESY Schülerlabor über Outreach und besonders schülertaugliche Erklärungsansätze.
https://bbb1.physnet.uni-hamburg.de/b/ale-1gt-ghb-rrk
Discussion round with Maike Lieser, Experiment System Engineer at European Space Agency. Feel free to ask queston about her carrer.
https://bbb1.physnet.uni-hamburg.de/b/mel-68c-dbz-ptk
https://bbb1.physnet.uni-hamburg.de/b/mel-eow-ky0-nil
Nicht erst die Corona-Pandemie hat gezeigt, dass es gute Wissenschaftsjournalisten braucht, die komplizierte Zusammenhänge verständlich erklären können. Zwar gehört es zum journalistischen Handwerk, sich auch in neue Themen einzuarbeiten, besser ist allerdings, wenn ein Grundverständnis vorhanden ist. Doch wie wird man als Physikerin zur Journalistin? Und worauf kommt es an?
https://bbb1.physnet.uni-hamburg.de/b/mel-eow-ky0-nil
Anna Henrichs hat an der RWTH Aachen Physik studiert, 2012 an der Georg-August-Universität Göttingen in experimenteller Teilchenphysik promoviert, und nach weiteren 2.5 Jahren als Postdoc an der Yale University, 2014 angefangen bei Google in Dublin zu arbeiten. Heute arbeitet sie als Data Analyst bei Google in Zürich und beschäftigt sich mit Massnahmen zur Missbrauchsbekämpfung und Sicherung von Nutzeraccounts.
In ihrem Vortrag wird sie darüber berichten, wie ihre Erfahrungen aus der Physik und einer internationalen Wissenschaftskollaboration am CERN ihr auch heute noch im Beruf helfen, und wie sie den Umstieg von der Wissenschaft zur Wirtschaft empfunden hat.
https://bbb1.physnet.uni-hamburg.de/b/mel-eow-ky0-nil
Maike Lieser , Experiment System Engineer at European Space Agency
I am a System Experiment Engineer at the European Space Agency (ESA) in the Netherlands. How did I end up there? I studied physics in Hannover and did my PhD at the Max Planck Institute for Gravitational Wave Physics. Already there I looked towards space and did my research on the instrument to measure gravitational waves with the LISA mission (Laser Interfermeter Space Antenna). Afterwards I went into industry - to Airbus, who we also worked together during my PhD project. Although I worked in a different part of the company, in the UK as a Mission System Engineer for science and earth observation missions. From there I went to ESA and now I work on science mission instrumentation. At Airbus, all our ESA projects had a Technical Officer, and now I am the Technical Officer! My work is to implement and follow national contributions from member states, usually these are scientific instruments or instrument sub-systems. My projects cover a very wide range of missions within the ESA Science programme: including astrophysics, fundamental physics and planetary exploration! I work together with scientists, but also with industry partners and of course with my colleagues at ESA.
https://bbb1.physnet.uni-hamburg.de/b/mel-eow-ky0-nil
Physikerinnen und Physikern im Wissenschaftsmanagement bietet sich ein breites Aufgabenspektrum. Im Vordergrund stehen dabei koordinierende Aufgaben, bei denen Lösungsorientierung, Multi-Tasking, Kommunikationsfähigkeit und diplomatisches Geschick erforderlich sind. Gefragt sind neben dem wissenschaftlichen Hintergrund meist eine Gesamtsicht und die Bereitschaft, sich in wechselnde Aufgaben einzuarbeiten, weniger die fachlich tiefe Auseinandersetzung mit einzelnen Fragestellungen. Eine der Herausforderungen für uns als Wissenschaftsmanagerinnen besteht darin, die Leitungsebene sowie die Wissenschaftlerinnen und Wissenschaftler effektiv zu unterstützen.
Nach meiner Doktorarbeit in der theoretischen Teilchenphysik habe ich mich vor 13 Jahren für den Weg ins Wissenschaftsmanagement entschieden. Zunächst war ich ca. drei Jahre als Referentin bei der Deutschen Forschungsgemeinschaft (DFG) in Bonn in der Gruppe ”Physik, Mathematik, Geowissenschaften” tätig. Nun bin ich seit mehr als neun Jahren in der Helmholtz-Gemeinschaft am Karlsruher Institut für Technologie (KIT), wo ich über die Jahre verschiedene Stellen mit unterschiedlichen Aufgaben inne hatte.
In dem Vortrag werde ich meinen Weg ins Wissenschaftsmanagement und – anhand von Beispielen aus verschiedenen Stationen meines Arbeitslebens – einige Anforderungen, Aufgaben und Herausforderungen der abwechslungsreichen Arbeit im Wissenschaftsmanagement vorstellen.
https://bbb1.physnet.uni-hamburg.de/b/mel-eow-ky0-nil
Exoplanet research, despite its young age, has come a long way in recent years, and a plethora of elements have been discovered in their atmospheres to date, such as water, iron, sodium and others.
However, without the possibility of launching a probe to these far-away worlds, an in-depth study of their atmospheric structure remains a challenge. In this talk, I would like to summarise the current state of the art in studying exoplanet wind patterns, starting with the two extremes: the lower atmosphere with its jet-like structures much like our Jupiter and the far-out exosphere with huge streams of escaping particles (see Ehrenreich et al. 2015, Bourrier et al. 2018 and Parmentier et al. 2013, 2018).
I will then show how we can connect these two areas and provide a full picture of the exoplanet atmospheric dynamics by using spectroscopic lines to probe the intermediate layers of the atmosphere via Doppler-broadening (Seidel et al. 2019, 2020a).
In many respects, planetary systems of low mass stars, so called red dwarfs or M-stars, differ from systems around medium or high mass stars. They contain different populations of planets. Many of these low mass stars host Earth to Neptune-mass planets but only a few harbor gas giants, like Jupiter or Saturn. Another peculiarity is related to debris discs around these cool stars. Debris discs are second generation, dusty circumstellar discs. They formed by collisions of planetesimals left over from the period of planet formation. Our Solar System, with a medium mass star, hosts a debris disc. It mainly consists of the Kuiper and Asteroid belt. But while during the last few decades many debris discs have been found and resolved around medium to high mass stars, only a handful of them have been discovered around low mass stars. In my current paper I look at this missing disc problem from the observational side. Is it possible that we do not see these discs because the telescopes are not able to detect them or is it more likely that they do not exist?
Very little is known about giant planets and brown dwarfs at an orbital separation great than 5 AU. And yet, these are important puzzle pieces needed for constraining the uncertainties that exist in giant planet formation and evolutionary models. Furthermore, evolutionary models of giant planets and brown dwarfs are plagued by a lack of observational constraints. The complex molecular chemistry of their atmospheres leaves a relatively wide parameter space for models to span.
To date, individual dynamical masses are known for only a handful of brown dwarfs, therefore any new detections contributes greatly to brown dwarf models as they provide important analogues for the characterisation of exoplanets. Radial-velocity measurements provide only a lower limit on the measured masses due to the unknown orbital inclination. Therefore directly imaging these candidates is needed to break that degeneracy and provide constraints on the dynamical mass of the companion.
I have selected ideal targets for direct imaging using the radial-velocity CORALIE survey for southern extra-solar planets with over 20 years worth of data containing a volume-limited sample of 1647 low-mass main sequence stars within 50 parsecs. As massive planets and brown dwarf companions are rare, one benefits from the CORALIE survey where we are able to identify golden targets for direct imaging. Detecting these giant companion candidates allows us to bridge the gap between radial-velocity-detected exoplanets and directly-imaged planets and brown dwarfs. I describe the progress towards the detection, characterisation and monitoring of widely-separated giant planets and brown dwarfs through both direct imaging and long-period radial-velocities. This includes the detection of several long-period radial-velocity giant planets and brown dwarfs, as well as the direct imaging of some of these companions with VLT/SPHERE and the discovery of a benchmark ∼50MJup T-type brown dwarf. The discovery of such benchmark sources provides a powerful and critical tool of advanced evolutionary models.
As we move toward imaging smaller and smaller objects it is important to use these objects as a laboratory to test theoretical atmospheric models. The components of detecting long-period massive-companions helps to probe a parameter space in mass, separation and age where the occurrence rate of these objects is not well understood. They also serve as a stepping stone towards detecting smaller and smaller exoplanets using both of these methods of detection.
On the basis of real-time {\it ab initio} calculations, we study the non-perturbative interaction of two-color laser pulses with MgO crystal in the strong-field regime to generate isolated attosecond pulse (IAP) from high-harmonic emissions from MgO crystal.
In this regard, we examine the impact of incident pulse characteristics such as its shape, intensity, and ellipticity as well as the consequence of the crystal anisotropy on the emitted harmonics and their corresponding IAPs.
Our calculations predict the creation of IAPs with a duration of $\sim$ 300 attoseconds;
in addition, using elliptical driving pulses, the generation of elliptical IAPs is shown.
Our work prepares future all solid-state compact optical devices offering perspectives beyond traditional IAP emitted from atoms.
Atoms and molecules in electronically excited states are referred to as metastable, if their decay to lower-lying states is forbidden by electric-dipole selection rules. Owing to their high electronic energy, metastable species can induce the ionization of other atoms or molecules upon collision, a process often referred to as autoionization. Autoionization processes are of great importance in the Earth's upper atmosphere, where metastable atoms and molecules are generated by UV photolysis and electric discharges. To date, the properties of many metastable species are still poorly understood.
In a proof-of-principle experiment, we demonstrate that metastable nitric oxide molecules, NO(a), and metastable N_2 molecules, generated inside a pulsed, supersonic beam, can be sensitively detected by reactive gas-phase collisions with ground- and excited-state Li atoms. Since the internal energy of NO(a) in the rovibrational ground state is lower than the ionization potential of Li in the 2^2S_{1/2} electronic ground state, autoionization is strongly suppressed for NO(a)-Li(2^2S_{1/2}) collisions. Using this detection method, we infer densities of only 300 NO(a) molecules/cm^3 and 3x10^4 metastable N_2 molecules/cm^3 in the interaction region. Our results also allow for an estimate of the vibrational-state population of NO(a) prior to the collision process.
Superconducting radio frequency (SRF) niobium cavities are the basic building blocks of linear accelerators present in modern x-ray free electron lasers, such as the European X-Ray Free-Electron Laser. The final surface treatment steps of Nb cavities impose a subtle change in their performance to obtain high quality factors at high accelerating field gradients; however, the underlying physical phenomenon is not fully understood yet. Here we report on the surface analysis of cavity-grade and high purity single-crystal Nb samples subjected to various thermal and gas exposure protocols together with the cavities and how the findings correlate with observed SRF properties. Surface characterization was performed by means of x-ray photoelectron spectroscopy, electron microscopy, energy dispersive X-ray spectroscopy and time-of-flight secondary ion mass spectroscopy. By in-situ monitoring of elemental composition in the near surface region before and after the N-infusion of Nb(100) model system, in ultra-high vacuum and much lower nitrogen partial pressures, a clear evidence of the formation of Nb-N bond is obtained together with the already known phases of Nb2O5, NbC, NbO2 and NbO. These results give a deeper insight of the surface composition changes occurring during the thermal cycles of Nb - including or excluding nitrogen in the low temperature bake step, and thus help us to correlate this to the improved RF cavity performance.
Photo Injector Test facility at DESY in Zeuthen (PITZ) utilizes slit scan technique as a standard tool for reconstruction of horizontal and vertical phase spaces because of its space charge dominated electron beams. A novel method for 4-dimensional transverse beam phase space measurement is proposed at PITZ known as Virtual Pepper Pot that can give insight to transverse beam phase space coupling. It utilizes the slit scans to form pepper-pot like beamlets by careful crossing and post processing of the slit scan data. All elements of the 4D transverse beam matrix are calculated and used to obtain the 4D transverse emittance, 4D kinematic beam invariant and coupling factors. The proposed technique has been applied to experimental data from the PITZ photo injector and compared with slit scan results.
https://bbb1.physnet.uni-hamburg.de/b/mel-pfx-pau-34j
Seit 1997 gab es jedes Jahr eine (Deutsche) Physikerinnentagung und vorher gab es regelmäßige Physikerinnentreffen. Es wurde jeweils über die aktuelle Situation der Physikerinnen berichtet, es wurde über universitäre und außeruniversitäre Arbeitsmöglichkeiten informiert und als Highlight gab es Vorträge von Physikerinnen, die ihre vielfältigen Forschungsprojekte präsentierten.
Die (DPT) Tagung vermittelte Studentinnen, dass es auch für sie Vorbilder gibt, dass sich Karriere und Familie miteinander verbinden lassen, dass der Beruf der Physikerin oder Physiklehrerin eine attraktive Option für Frauen darstellt. Es gab Möglichkeiten zum Mentoring und zur Netzwerkbildung auf allen Statusebenen.
Im letzten Jahr gaben die Teilnehmerinnen auf der Physikerinnentagung in Berlin ein eindeutiges Votum für den Fortbestand dieser Tagung. Egal, ob als eigenständige Tagung oder mit Unterstützung und Anerkennung unserer Fachorganisation, der DPG.
Deshalb findet in diesem Jahr trotz Covid-19-Pandemie die Tagung statt, diesmal als Online-Tagung für Physikerinnen.
Wie soll es nun weitergehen?
Seit einem Vierteljahrhundert haben es Physikerinnen geschafft, sich zu organisieren und die Besonderheiten ihrer Situation in ihrem Umfeld zu analysieren. Viele der damit verbundenen Probleme wurden angegangen bzw. beseitigt, aber es gibt noch viel zu tun.
Wir möchten uns über die Zukunft der Physikerinnentagung austauschen, Ideen für die 25. Tagung sammeln und gleichzeitig unsere Erfolge auch gebührend feiern.
The poster authors have uploaded a video of their poster contribution in advance. The Q&A session can be used to ask questions and have discussions about the posters. Therefor, each author will await you in a dedicated room.
A promising approach for monolithic integration of III-V semiconductors on Si
https://bbb1.physnet.uni-hamburg.de/b/ale-w3u-dwk-czi
22 Jahre AKC: Erzielte Erfolge und zukünftige Ziele
https://bbb1.physnet.uni-hamburg.de/b/ale-vns-egr-cu2
Tailor-Made Anodic Aluminum Oxide Photonic Crystals for Photocatalytic Applications
https://bbb1.physnet.uni-hamburg.de/b/ale-xon-p6h-lka
Strain engineering in two-dimensional materials
https://bbb1.physnet.uni-hamburg.de/b/ale-mwi-pu7-di7
MooNpics – A European wide metrology round-robin test
In case of questions: silja.schmidtchen@xfel.eu
Building bridges for the next generation of physicists in Halle
https://uni-hamburg.zoom.us/j/95069112930?pwd=THpFWDlZQjYrcHpGcnluUDA2QUVydz09
Meeting-ID: 950 6911 2930
Impact of COVID-19 Crisis on Work-Life Balance
https://bbb1.physnet.uni-hamburg.de/b/ale-u42-qag-zqz
Inisight into planetary groth: Influence of high temperatures on chondritic material
https://bbb1.physnet.uni-hamburg.de/b/ale-vj5-azv-roe
Non-linear Compton Study in the LUXE Experiment
https://bbb1.physnet.uni-hamburg.de/b/ale-4po-dd3-kew
Physikerinnen: Aktuelle Zahlen und Fakten
https://bbb1.physnet.uni-hamburg.de/b/ale-b84-nkd-qzc
Optical Cross Coupling in Space-Based Gravitational Wave Detectors
https://bbb1.physnet.uni-hamburg.de/b/ale-qda-tkm-dyb
Mit diesem Poster stellen wir Euch den Arbeitskreis Chancengleichheit (AKC) vor, eine fachübergreifende Vereinigung innerhalb der Deutschen Physikalischen Gesellschaft (DPG) mit über 570 Mitgliedern. Wir engagieren uns für die Belange von Physikerinnen, für bessere Rahmenbedingungen und Strukturen, um Chancengleichheit zu erreichen. Hier geben wir einen Überblick über die Geschichte des AKCs von der Idee über die Gründung bis zum heutigen Zeitpunkt. Dabei zeigen wir zahlreiche Meilensteine auf, beginnend mit der Schaffung des AKCs selbst, und die vielfältigen Aufgaben, die unsere AKC Kommission und ihre Unterstützerinnen erfüllen. Ausgehend von der jetzigen Situation beleuchten wir die Möglichkeiten für die Zukunft und laden Euch ein, trotz des ungewohnten Formates der Tagung, Euch aktiv daran zu beteiligen und uns Eure Meinung, Wünsche und Ziele mitzuteilen.
III-V semiconductors have been a topic of technological interest owing to their intriguing properties like high carrier mobility and direct fundamental bandgap. Si, on the other hand forms the backbone of electronic engineering but is an indirect bandgap semiconductor. The idea here is to integrate both III-V material and Si on a single platform with high structural quality and excellent optoelectronic properties. This comes with a number of challenges as both Si and III-V semiconductors are heterogeneous material due to mismatches in lattice constants, thermal expansion coefficients, different lattice symmetries and different polarities at the heterojunction. As a result, the material can possess several crystal defects which can degrade the performance of the device. We use a distinctive approach, “nanoheteroepitaxy”, to grow high quality, defect free III-V materials selectively on Si nanotips patterned substrates. It allows growth on well-defined areas on the substrate, leads to limited surface contact, and enables elastic relaxation of strain. We present the selective epitaxial growth of InP and GaP using Gas Source Molecular Beam Epitaxy on arrays of Si nanotips with different openings, ranging from 8 nm to 62 nm and pitch distance varying from 0.5 µm x 0.5 µm to 2 µm x 2 µm, embedded in SiO2 matrix. Our approach brings freedom in tailoring the III-V material and leads to a myriad of opportunities to investigating III-V/Si selective growth, and realization of efficient optoelectronic devices on the Si platform.
Changing key competencies for learners, society and the labor market require contemporary concepts for teaching, learning, and managing school education systems. This includes field-based hands-on learning. The internships at the Students Laboratory for Physics and the Max Planck Institute for Microstructure Physics, both in Halle, are paradigm examples of extracurricular learning experiences for students in Germany.
https://uni-hamburg.zoom.us/j/95069112930?pwd=THpFWDlZQjYrcHpGcnluUDA2QUVydz09
Meeting-ID: 950 6911 2930
In response to COVID-19 crisis, Working Group Equal Opportunities of the German Physical Society conducted a global survey between April and June 2020. The aim of the "Impact of COVID-19 Crisis on Work-Life Balance" survey was to learn about the impact of the pandemic to our work and social lives. Working Group for Equal Opportunities (AKC) of the German Physical Society (DPG) strives to provide guidance to all relevant parties such as institutes, NGOs, employers, employees, and managers by serving the results of this survey which is based on responses of more than 1500 participants worldwide.
In this study, living arrangements, remote working conditions, self-organization and leadership attitudes and post-pandemic concerns compared for different demographic, regional, educational, and occupational groups. Stress level due to remote working, changed lifestyles and different perceptions about the post-pandemic era were investigated.
Planetary growth in protoplanetary disks starts with dust particles colliding, sticking to each other and growing in size up to the cm-range. Further accretion in this range is hindered by bouncing and fragmentation of colliding agglomerates. The growth of planetesimals above the so called “bouncing barrier” is still not fully understood. Compositional and concomitant structural changes induced by high temperatures in the vicinity of the protostar might explain improved sticking even beyond the bouncing barrier.
As meteorites contain primordial phases representing the material in our young solar system, studying their properties can give insight into the processes of planetry formation. To simulate conditions in protoplanetary disks we heated chondritic material up to 1400K in vacuum. Via $\mathrm{^{57}}$Fe Mössbauer spectroscopy and synchrotron powder x-ray diffraction thermal changes of magnetic, compositional and structural changes were investigated.
We observe a decrease of iron oxide content with high temperatures up to a point where only iron bearing silicates can be found in the material. These modifications of chondrites can alter their potential for future planetesimal formation.
Funding by the DFG (project WE 2623/19-1 and WU 321/18-1) is gratefully acknowledged.
With new light sources, like free electron lasers and ultimate storage rings, diffraction limited X-ray radiation will become available for new classes of scientific and technological applications.
These light sources are characterised by very low wavelengths, high brilliance and full coherence of the beam. To preserve these properties along the beam propagation path, highly precise diffraction limited optics are needed, leading to ambitious requirements for the X-ray mirrors used in such a machine and therefore generating high demands on the manufacturers as well as on the metrology.
To face these questions, the “MooNpics – Metrology On One-Nanometer-Precise Optics” has been established as a work package of the CALIPSOplus European project. Within the MooNpics project 12 partners collaborate to improve mirror metrology and mirror manufacturing techniques. The goal is to push the frontiers in mirror metrology in Europe to a single-nanometre figure error precision, thus fulfilling the new requirements.
Part of the MooNpics project is a European wide round-robin test started in October 2018. Three X-ray mirrors are sent to 11 metrology laboratories all over Europe and measured with different measurement techniques in order to improve existing metrology methods and manufacturing techniques. All partners contribute with excellent know-how in nanometre precise metrology and with superior equipped metrology laboratories. With the final results it will be possible to establish standards for metrology measurement methods and mirror mountings. Furthermore, calibrated test mirrors can be created. Methods for spatial characterisation with wavefront metrology are optimised, in order to provide fast and accurate beam profile characterisation and optics alignment.
Contact details: silja.schmidtchen@xfel.eu
The electron beam accelerator of the European XFEL, operated at DESY, is the highest energy electron beam currently operating world-wide.While it was designed for the purpose of photon science it is also ideally suited to study quantum physics in the strong-field regime.This is the goal of the LUXE experiment currently being designed by DESY accelerator, particle and laser physicists jointly with collaborators from Germany, Israel, Ukraine and UK. As one of the goals, LUXE experiment will measure the non-linear Compton, often referred as High Intensity Compton scattering (HICS) and the two-step trident process in a new regime. In one of the modes, LUXE will collide the electron beam with the high-power laser pulse. With these measurements, the LUXE experiment will advance the field significantly compared to previous experiments.
Gravitational waves are a hot topic in science at least since Rainer Weiss, Kip Thorne and Barry Barish got the Nobel prize in 2017. The LIGO and Virgo collaborations have presented us with exceptional detections in the last years and will continue even more so in the future. However, there are gravitational waves that cannot be detected from ground. The future space based gravitational wave detector LISA will therefore enrich the gravitational wave science with additional sources and scientific questions. LISA will consist of three spacecraft exchanging laser beams over a distance of 2.5 million kilometers. One of the most relevant optical noise sources in LISA, is the coupling of unwanted space craft motion into the phase readout, also called Tilt-To-Length (TTL) coupling. This noise was already observed during the technology demonstration mission LISA Pathfinder (2015-2017), and dedicated experiments were performed to study this noise type in detail.
In my talk, I will briefly introduce the LISA and LISA Pathfinder missions. Based on this, I will explain TTL noise and how it couples into the phase readout. I will describe how geometric and non-geometric effects contribute and show why a detailed analysis of TTL is a complex problem.
Es werden aktuelle Daten zum Anteil der Physikerinnen und die entsprechende Entwicklung in den letzten Jahren präsentiert.
Wie viele Physikerinnen gibt es eigentlich in Deutschland? Werden Frauen immer noch benachteiligt? Und gibt es mittlerweile genügend weibliche Vorbilder in der Physik - insbesondere hinsichtlich der Vereinbarkeit von Familie und Beruf?
Der Arbeitskreis Chancengleichheit (AKC) der Deutschen Physikalischen Gesellschaft (DPG) stellt regelmäßig solche Daten zusammen. Als Quelle dient das statistische Bundesamt sowie eigene Erhebungen innerhalb der DPG. Diese Daten werden vorgestellt.
Two-dimensional (2D) carrier systems in semiconductors are popular in industrial device applications as well as in fundamental research to study quantum effects at low temperatures. The advent of van-der-Waals (vdW) materials, i.e., 2D materials that can be separated into individual atomic layers by breaking the vdW-bonds, are promising candidates towards using mechanical methods to control the electronic properties.
Elastic strain applied to a 2D material directly affects the atomic lattice of a material by changing the distance of the chemical bonds and the lattice symmetry. Different approaches can be used to introduce strain to a 2D vdW system. These approaches can be divided into two main categories: The first category is using a static strain induced through a patterned substrate, for example. A more advantageous approach, however, is continuously modifying the strain during the measurement, e.g. through the deformation of a substrate in situ.
I will present and introduce possible methods to induce strain and show preliminary measurements on graphene.
Anodic aluminum oxide (AAO) membranes feature self-organized, highly ordered cylindrical pores with distinct geometrical characteristics such as pore length and diameter, interpore distance, and barrier layer thickness. Modifying the electrochemical anodization parameters and applying pulse-like anodization profiles tailors the pore morphology, specifically the diameter, from straight to periodically modulated structures such as distributed Bragg reflectors or gradient index filters. Accordingly, the membranes act as photonic crystals (PCs) and exhibit photonic stopbands in which light propagation is forbidden. Incoming photons of wavelengths near the stopband edges are slowed down within the tailored structure due to the so-called slow photon effect. This phenomenon results in an increased interaction probability of the photons with the PC material, hence, making such structures very attractive for photocatalytic applications. The photocatalytic performance of AAO-PCs can be further enhanced by functionalizing the surface with photocatalytically active materials (e.g. TiO$_2$, ZnO, WO$_3$) or tuning the photonic stopband position of the AAO by adapting the pore morphology. Herein, surface modifications of AAO-PCs by atomic layer deposition (ALD)—a deposition method based on sequential, self-limiting gas-solid surface reaction—are conducted and the degradation of methylene blue is studied to assess the photocatalytic properties of these PC structures. Optimizing and combining the different preparation strategies to further improve the photocatalytic efficiency and to tune the wavelength selectivity of AAO-PCs could expand their utilization as tailor-made photocatalysts.
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
Laura Winterling entführt Ihre Zuhörer mit 28.000km/h auf eine faszinierende Reise in den ALL-Tag und erörtert die immer noch bestehende Frage: Frauen in Männerdomänen? Alltag, oder schon Realität? Schauen Sie mit Frau Winterling auf diese Fragestellung von einer anderen Perspektive. Mit Eindrücken aus 400km Höhe soll ergründet werden was es tatsächlich braucht, um erfolgreich in die eigenen Zukunft zu starten. Wir dürfen gespannt erfahren, was wir uns dafür von Astronauten auf der ISS dafür abschauen können.
https://bbb1.physnet.uni-hamburg.de/b/ale-1gt-ghb-rrk
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq
The first detection of gravitational waves in 2015 by the LIGO detectors, created by the merger of black holes more than a billion years ago, was followed by several other signals from black holes. In 2017, the merger of neutron stars was detected by LIGO and Virgo detectors and by gamma-ray telescopes, and was found by many electromagnetic observations too: a new era of gravitational wave astrophysics has started with very bright prospects for the future. LIGO and Virgo took data again for a year in 2019-2020, and many more merging black holes and neutron stars have been discovered. We will describe the technology involved in the LIGO gravitational wave detectors, details of the latest discoveries and the exciting prospects for more detections in the next years.
Ein Science Slam ist ein Wettbewerb in dem Teilnehmerinnen einen wissenschaftlichen Text auf unterhaltsame Weise vortragen. Es ist eine Kunstform die an den Poetry Slam angelehnt ist, bei dem literarische Kurztexte auf eine ähnliche Weise vorgetragen werden. Für ihre Darbietung steht den Vortragenden nur ein begrenzter Zeitrahmen zur Verfügung. Anschließend hat das Publikum die Möglichkeit online über die besten Vorträge abzustimmen. Die Gewinnerinnen erhalten einen Preis für ihren online Auftritt.
Der Science Slam wird moderiert von der Poerty Slam Künstlerin Anna Bartling, die mit ihren Auftritten regelmäßig ein großes Publikum begeistert.
Die Moderation wird auf Englisch sein. Den Teilnehmerinnen ist es freigestellt welche Sprache sie für ihren Beitrag wählen.
A science slam is a competition in which participants present a scientific text in an entertaining way. It is an art form that is based on the poetry slam, in which short literary texts are presented in a similar way. The speakers only have a limited time frame for their presentation. The audience then has the opportunity to vote online for the best presentations. The winners will receive a prize for their online performance.
The Science Slam is moderated by the Poerty Slam artist Anna Bartling, who regularly inspires a large audience with her performances.
The moderation will be in English. It is up to the participants which language they choose for their contribution.
https://bbb1.physnet.uni-hamburg.de/b/ale-yuu-pds-rpq