This talk will present our recent work on the use of arrays of Rydberg atoms to study quantum magnetism and to generate entangled states useful for quantum metrology. We rely on laser-cooled ensembles of up to hundred individual atoms trapped in microscopic optical tweezer arrays. By exciting the atoms into Rydberg states, we make them interact by the resonant dipole interaction. The system...
Optical tweezer trapping of neutral atom arrays has been a rapidly progressing platform for quantum information science, enabling control and detection of 100s of individual atomic qubits, and incorporation of different kinds of interactions. While pioneering work focused on alkali species, there has been recent exploration of a new type of atom - alkaline-earth(-like) atoms - for optical...
Advances in quantum manipulation of molecules bring unique opportunities: the use of molecules to search for new physics; exploring chemical reactions in the ultra-low temperature regime; and harnessing molecular resources for quantum simulation and computation. I will introduce our approaches to building individual ultracold molecules in optical tweezer arrays with full quantum state control....
Itinerant spin polarons - bound quasiparticle states of magnons and charge dopants - have been predicted to emerge in two-dimensional Fermi-Hubbard models with frustration. These polarons are expected to be robust even at high temperatures since their binding energy is on the tunneling, rather than superexchange, energy scale. Indirect signatures of their existence have been observed in...
Precise and rapid control of quantum states is crucial in modern quantum technologies. Adiabatic following, such as adiabatic rapid passage (ARP) and stimulated Raman adiabatic passage (STIRAP), offers an effective method for gradually connecting initial and final states. Spatial adiabatic passage (SAP) is an intriguing extension of STIRAP that enables the transfer of a wave packet between...
Many-body quantum systems are very difficult to simulate with classical
computers, as the computational resources (time and memory) usually grow exponentially
with the size of the system. However, quantum computers and analog quantum simulators
can perform that task much more efficiently. In this talk, I will first show how those
devices can be use to compute physical properties at...
The study of space-continuous quantum physics in the many-body limit is natural for ultracold gas systems. The term Quantum ‘Field’ Simulators emphasizes the continuum aspect of space-time as well as the quasi-continuous observables such as density, phase and collective spin.
In this talk, I will present how one can use the system of a two-dimensional potassium gas to simulate the dynamics...
The recently proposed exact quantum solution for two δ-function-interacting particles with a mass-ratio 3:1 in a hard-wall box [Y. Liu, F. Qi, Y. Zhang and S. Chen, iScience 22, 181 (2019)] seemingly violates Gaudin's necessary condition for the Bethe Ansatz integrability of a system of semitransparent δ-function mirrors. This condition requires that if two mirrors cross at a dihedral angle...
Atomtronics is the emerging quantum technology of matter-wave circuits which coherently guide propagating ultra-cold atoms. The field benefits from the remarkable progress recently achieved in micro optics, allowing to control the coherent matter with enhanced flexibility on the micro-meter spatial scale. This way, both fundamental studies in quantum science and technological applications can...
We experimentally study the paradigmatic many-body problem of mobile impurities interacting with a homogeneous Bose-Einstein condensate (BEC). We use a combination of injection spectroscopy and many-body interferometry to access the injection spectrum (frequency domain) and the impurity-coherence function (time domain). Our experiments start with a spin-polarized BEC confined in an optical box...
Recent experimental advances of quantum simulators allow unprecedented microscopic studies of the structure of strongly correlated quantum matter. In the Fermi-Hubbard model, believed to underly high-Tc superconductivity and accessible to ultracold atom experiments in optical lattices, this allows to study the origins of unconventional pairing from a new perspective — a long-awaited goal of...
The Fermi-Hubbard model is an iconic model of solid state physics that is believed to capture the intricate physics of strongly correlated phases of matter, including high-Tc superconductivity. Such a state of matter is supposedly achieved upon doping a cold antiferromagnetic Mott insulator, and magnetically mediated charge ordering in the form of pairing of dopants (holes), in particular, is...
We developed a new advanced ultra-cold Dysprosium (Dy) apparatus, which incorporates a quantum gas microscope (QGM) with a resolution of a quarter micrometer. The QGM and the cooling
and trapping regions are within the same vacuum glass vessel assuring simple atom transport between them. We demonstrate the essential experimental steps of laser and evaporative cooling,
lattice loading,...
Discrete time crystals created in a Bose-Einstein condensate of ultracold atoms bouncing on an oscillating mirror [1] can exhibit dramatic breaking of time-translation symmetry [2, 3], allowing the creation of discrete time crystals having tens of temporal lattice sites and suitable for hosting a broad range of condensed matter phenomena in the time dimension [4].
We will discuss temporal...
Adiabatic protocols are employed across a variety of quantum technologies, from implementing state preparation and individual operations that are building blocks of larger devices, to higher-level protocols in quantum annealing and adiabatic quantum computation. The problem of speeding up these processes has garnered a large amount of interest, resulting in a menagerie of approaches, most...
Floquet engineering is an important tool for realizing topologically nontrivial band structures for charge-neutral atoms in optical lattices. However, the preparation of a topological-band-insulator-type state of fermions, with one nontrivial quasi-energy band filled completely and the others empty, is challenging as a result of both driving induced heating as well as imperfect adiabatic state...
Quantum science promises great potential to revolutionize our current technologies. The past few years have witnessed a rapid progress on using arrays of individually trapped atoms as a programmable quantum processor. However, several predominant challenges remain, including reconfigurable individual addressability for qubit/spin operation and non-demolish selective detection, which lead to...
The relationship between many-body interactions and dimensionality is key to emergent quantum phenomena. A striking example is the Bose gas, which upon confinement to one dimension (1D) obeys an infinite set of conservation laws, prohibiting thermalization and steering dynamics. We experimentally demonstrate that the integrable dynamics of a Bose gas can persist deep within the dimensional...
Whether discussing interacting many-body physics with cold atoms, quantum metrology, or quantum computing, there are important questions around how large an entangled many-body state we can usefully and reliably prepare in analogue quantum simulators subject to decoherence. Given that information spreading and entanglement growth are limited by Lieb-Robinson bounds, the useful system size will...
We shall present our results for the fourth cluster coefficients of the homogeneous unitary spin 1/2 Fermi gas as functions of the internal-state mass ratio, over intervals constrained by the 3- or 4-body Efimov effect. For this we use the Endo-Castin 2016 conjecture (validated for equal masses by Hou and Drut in 2020) in a numerically efficient formulation making the sum over angular momentum...
Negative absolute temperature entails a situation where the entropy of a closed system reduces as the internal energy increases, and this leads to the peculiar situation that atoms in a band dominantly occupy the highest energy states in the band. Here we report the observation of negative absolute temperatures in a triangular optical lattice—a non-bipartite lattice where geometric...
We consider a quasi-one-dimensional dipolar condensate in a step-like analogue black hole setup. It is shown that the existence of roton excitations impacts significantly the Hawking radiation spectrum:
The emitted radiation depends on the depth of the roton minimum, and is in general more intense. In addition, we find a novel spontaneous particle creation mechanism with no counterpart in...
Crossing a continuous phase transition results in the formation of topological defects with a density predicted by the Kibble-Zurek mechanism (KZM). We report on two predictions beyond KZM:
First, it is shown that the statistics of defects follow a binomial distribution with N Bernoulli trials associated with the probability of forming a topological defect at the locations where multiple...
Dysprosium is a fascinating candidate for studying cooperative and collective effects in dense ultra-cold media. With the largest groundstate magnetic moment of all elements in the periodic table (10 Bohrmagnetons), it offers a platform to study the effect on scattering of light due to competition between magnetic dipole-dipole interactions (DDI) and light induced correlations. In a...
Very recent advances on dipoles in optical lattices and tweezer arrays are opening many intriguing novel possibilities, both for the simulation of Hubbard models and of spin models. I will first comment on extended Hubbard models, showing how strong inter-site interactions lead to a peculiar dynamics, characterized by Hilbert-space shattering and interaction-induced localization in absence of...
Motivated by a recent experiment on a square-lattice Rydberg atom array realizing a long-range dipolar XY model [Chen et al., Nature (2023)], we numerically study the model's equilibrium properties. We obtain the phase diagram, critical properties, entropies, variance of the magnetization, and site-resolved correlation functions. We consider both ferromagnetic and antiferromagnetic...
The effect of dipolar interactions on harmonically trapped BECs has been the subject of intense and fruitful research over recent years, but despite being theoretically calculated over 15 years ago [1] the modification of the BEC transition temperature due to dipole-dipole interactions has, up to now, not been experimentally observed. We will present our experimental findings on this topic;...
One-dimensional gases offer a convenient and flexible platform for investigating open problems in modern physics, such as the full understanding of strongly interacting, out-of-equilibrium quantum systems. In particular, this work focuses on strongly repulsive one-dimensional gases consisting of two equally balanced spin components under a box confinement. To induce nonequilibrium dynamics,...
We consider the far-from-equilibrium quantum transport dynamics in a 1D Josephson junction chain of multi-mode Bose-Einstein condensates. We develop a theoretical model to examine the experiment of R. Labouvie et al. [Phys. Rev. Lett. 115, 050601 (2015)], wherein the phenomenon of negative differential conductivity (NDC) was reported in the refilling dynamics of an initially depleted...
Due to anisotropic long-range interactions, degenerate ultra-cold dipolar gases of Erbium and Dysprosium exhibit supersolidity, an exotic phase of matter both density-modulated and phase coherent. It is theorized that these supersolids maintain their phase coherence due to a superfluid background. While density modulation can be directly observed and phase coherence emerges from...
We report on recent breakthroughs in two experiments employing Feshbach-resonant mixtures of fermions.
In radio-frequency spectroscopic measurements on fermionic $^{40}$K (or bosonic $^{41}$K) atoms immersed as impurities in a Fermi sea of $^6$Li atoms, we observed mediated polaron-polaron interactions [1]. Our results confirm the prediction of Fermi-liquid theory that the sign of this...
The ground-state properties of two-component bosonic mixtures in a one-dimensional optical
lattice are studied both from few- and many-body perspectives. We rely directly on a microscopic Hamiltonian with attractive inter-component and repulsive intra-component interactions to
demonstrate the formation of a quantum liquid. We reveal that its formation and stability can be
interpreted in...
Gauge theories, a fundamental framework of modern physics, govern the intricate dynamics of elementary particles that constitute the world we know of. The decades-long quest to understand quantum systems operating under gauge symmetries presents both theoretical and experimental interests, with applications ranging from early-universe cosmology and heavy-ion collisions to condensed matter...
The realization of the Bose-Hubbard model with cold atoms, twenty years ago, can be considered the birth of quantum simulation. Today, advanced quantum simulators provide us with the opportunity to explore more exotic models, including models with flat energy bands, multi-band models, or models with long-range interactions. In these contexts, I discuss the intriguing scenario of Bose-Einstein...
Models of quantum many-body phases of matter may be realized using fermionic ultracold atoms in place of the electrons, and engineered optical potentials to emulate a crystal lattice. Quantum simulation of this kind takes advantage of the capability to adhere to a theoretical model, while the tunability of model parameters enables quantitative comparison with theory.
As an example,...
A quantum Hall system is characterized by non-trivial topological order of its underlying quantum states. While topological order cannot be accessed using local measurements, it leads to specific signatures in the structure of entanglement upon spatial partition, characterized by the entanglement spectrum. According to the Li-Haldane conjecture, the entanglement spectrum corresponds to a...
Resonantly interacting mixtures of ultracold fermionic atoms provide versatile and highly controllable platforms with which to explore a wealth of phenomena occurring in strongly-correlated systems: from helium liquids and solid-state materials, up to nuclear and quark matter. Here, I will discuss recent progress of my experimental team in making, probing and characterizing novel 6Li-53Cr...
Diffusion Monte Carlo calculations on the possibility of having self-bound one-dimen-sional droplets of SU(6) $\times$ SU(2) ultracold fermionic mixtures are presented. We found that, even though arrangements with attractive interactions with only two spin types are not self-bound, mixtures with at least three kinds of fermions form stable small drops. However, that stabilization...
Quantum fluctuations can stabilize bosonic mixtures and Bose-Einstein condensates with dipolar interactions against the collapse predicted by the mean-field theory. This stabilization mechanism allows for two new states of matter to arise: self-bound quantum droplets and dipolar supersolids. When dipolar interactions between the atoms are present, the droplets can self-assemble into arrays and...
We show that a Tonks-Girardeau gas that is immersed in a Bose-Einstein condensate can undergo a transition to a crystal-like Mott state with regular spacing between the atoms without any externally imposed lattice potential. We characterise this phase transition as a function of the interspecies interaction and temperature of the Tonks gas, and show how it can be measured via accessible...
The interest in developing solid theoretical frameworks to describe analog quantum simulation arises from the diverse range of potential applications it offers in areas such as condensed-matter physics, high-energy physics or quantum chemistry, in an era where fully fault-tolerant operations have not yet taken over NISQ (noisy,
intermediate scale, quantum) devices. One of my previous work has...
Generation, storage and utilization of correlated many-body quantum states are crucial objectives of future quantum technologies and metrology. Such states can be generated by the spin-squeezing protocols. In this work [1-2], we consider the dynamical generation of spin squeezing in a lattice system composed of ultra-cold fermionic atoms in the Mott phase at half-filling. To induce the...
We report on the first quantum simulation of the Hall effect for strongly interacting fermions [1]. By performing direct measurements of current and charge polarization in an ultracold-atom simulator, we trace the buildup of the Hall response in a synthetic ladder pierced by a magnetic flux, going beyond stationary Hall voltage measurements in solid-state systems. We witness the onset of a...
A cornerstone in the description of quantum fluids is the Bogoliubov theory used to explain the emergence of superfluidity in ensembles of weakly-interacting bosons. At the microscopic level, this theory predicts that interactions deplete the condensate through the formation of pairs of bosons with opposite momenta, known as quantum depletion. Exploiting the capability to detect individual...
I will discuss the results of a theoretical investigation into the supersolid state of a dipolar quantum Bose gas confined within an infinite tube potential [1-3]. This system serves as a thermodynamic idealization of cigar-shaped dipolar Bose gases, which have been utilized in recent experiments to prepare supersolids [4]. Our study presents phase diagrams as a function of the average linear...
I present our anomaly in the temperature dependence of the thermodynamics of a one-dimensional Bose gas. The anomaly exists for any contact repulsive interaction strength and is a reminiscence of a superfluid-normal phase transition. It signals unpopulated states below the hole branch in the excitation spectrum. The anomaly temperature is of the order of the hole-branch maximal energy. The...
Measuring the temperature of an interacting fermionic cloud of atoms in the BCS limit represents a delicate task. In the literature temperature measurements have so far been only suggested in an indirect way, where one sweeps isentropically from the BCS to the BEC limit. Instead we suggest here a direct thermometry, which relies on measuring the column density and comparing the obtained data...
Our project aims to experimentally demonstrate that weakly interacting Bose condensed atoms bouncing on a periodically driven atomic mirror can spontaneously break time-translational symmetry to form a discrete time crystal [1]. The resonantly tuned bouncing ensemble can evolve along long-lived stable orbits with a period multiple times larger than the driving period [2] thus creating a large...
Quantum gas systems provide a unique experimental platform to study the crossover between Bose–Einstein condensed molecular pairs and Bardeen–Cooper–Schrieffer superfluidity. The few studies in optical lattices have so far focused on the case when only the lowest Bloch band is populated, thus excluding orbital degrees of freedom. Here we demonstrate the preparation of ultracold Feshbach...
Boyle's 1662 observation that the volume of a gas is, at constant temperature, inversely proportional to pressure, offered a prototypical example of how an equation of state (EoS) can succinctly capture key properties of a many-particle system. Such relations are now cornerstones of equilibrium thermodynamics. Extending thermodynamic concepts to far-from-equilibrium systems is of great...
The Hall effect, originating from the motion of charged particles in magnetic fields, has deep consequences for the description of materials, extending far beyond condensed matter where it was initially observed.
Understanding such an effect in interacting systems represents a formidable challenge, even for small magnetic fields.
Using an atomic quantum simulator where the motion of...
Lev Pitaeveskii, to whom this talk is dedicated, always had the passion for superfluid phenomena, to which he gave fundamental contributions either before and after the experimental realization of Bose-Einstein condensation in atomic gases. In this presentation I will discuss some recent results concerning the consequences of the breaking of translational invariance on the superfluid fraction...
Among the many topics to which Lev Pitaevskii has made an essential contribution, solitons occupy a central place. Lev explored many facets of their properties, such as the physical characterization of their mass, momentum and equation of motion [1]. In this talk, we will briefly review some types of solitons that have been observed in the context of quantum gases, before focusing on "magnetic...
With this commemorative talk, we pay tribute to the exceptional life and profound scientific contributions of Lev Pitaevskii, a world-leading scientist and mentor. The presentation provides a sincere reflection on his remarkable academic and scientific journey, encompassing significant milestones from writing a letter to Lev Landau in his youth, entering doctoral studies in Landau´s group,...
We have recently demonstrated microwave shielding and evaporative cooling for bosonic NaCs ground state molecules [1,2]. Dressing the molecules with a circularly polarized microwave field, we observe a suppression of inelastic loss by a factor of 200 and reach lifetimes of 1 second in dense molecular ensembles. We have demonstrated evaporative cooling for bosonic molecules and reached a...
Quantum simulation using ultracold atoms and molecules has opened a new research field to probe quantum matter in- and out-of-equilibrium. In fermionic quantum matter, mixed two-dimensional systems boost the pairing energy of holes and have enabled us to observe first signatures of stripe phases in doped systems. In quantum dynamics, probing the full counting statistics of charge transfer...
A key step in unraveling the mysteries of materials exhibiting unconventional superconductivity is to understand the underlying pairing mechanism. While it is widely agreed upon that the pairing glue in many of these systems originates from antiferromagnetic spin correlations, a microscopic description of pairs of charge carriers remains lacking.
In this talk, I will present a mechanism...
We present the progress towards constructing of a dipolar quantum gas microscope using dysprosium atoms. This new apparatus combines the single-site resolution of a quantum gas microscope with the long-range and anisotropic interactions found in dipolar quantum gases, allowing for detailed studies of strongly correlated quantum phases. We plan to do this using dysprosium atoms trapped in an...
We present our efforts towards a new quantum simulation and computation platform based on Yb Rydberg atoms in optical tweezers. Based on the so-called OMG Qu-Bit architecture [1] our approach promises efficient and robust options for storage, manipulation and read-out of quantum information based on the two-electron valence structure of Yb. Resource efficient schemes for error correction [2],...
Recent advances in the microscopic optical manipulation of cold atomic systems have extended our experimental control capabilities down to the level of single particles or single excitation quanta, providing exciting opportunities to explore quantum many-body problems with a novel bottom-up perspective. Here, I will describe ongoing work to develop a modern experimental apparatus in...
Dysprosium (Dy), as the most magnetically stable element, offers fascinating prospects for quantum gas research due to its strong anisotropic long-range dipole-dipole interactions competing with tunable short-range contact interactions. These properties have led to the discovery of novel many-body quantum states in recent years, including liquid-like droplets, droplet crystals, and...
Quantum gases with tunable interactions provide a versatile setting to study non-equilibrium dynamics. Here, we study Fermi gases following a rapid quench of the interaction strength and study the subsequent evolution. Within the superfluid phase, these quenches excite oscillations of the order parameter, which we observe directly using Bragg spectroscopy. These amplitude oscillations provide...
Quantum heat engines have been the subject of growing interest in recent years in the emerging field of quantum thermodynamics. Such engines can utilize uniquely quantum many-body effects to enhance the performance of classical engines, implying a quantum advantage. In my contribution, I will introduce and discuss the performance of a quantum many-body Otto cycle operating under a sudden...
Two-component dipolar condensates are now experimentally producible, and we theoretically investigate the nature of supersolidity in this system. In dipole-imbalanced situations we predict the existence of a binary supersolid state in which the two components form a series of alternating immiscible domains. In stark contrast to single-component supersolids, binary supersolids do not require...
Ultracold atoms loaded into higher Bloch bands provide an elegant setting for realizing many-body quantum states that spontaneously break time-reversal symmetry through the formation of chiral orbital order. The applicability of this strategy remains nonetheless limited due to the finite lifetime of atoms in high-energy bands. Here we introduce an alternative framework, suitable for bosonic...
Bose-Einstein condensates (BECs) are excellent systems for quantum sensing applications like navigation, relativistic geodesy and tests of the universality of free fall. The sensitivity of most such atom interferometers increases quadratically with the interrogation time, which makes it beneficial to extend the free fall time. To accomplish this goal NASA has launched the Cold Atom Lab (CAL)...
We present an overview of some aspects of the non-equilibrium dynamics of arrays of atoms/molecules that are coupled by the electromagnetic field, considering both low-frequency (MW) and high-frequency (optical) regimes for the relevant transitions.
Quantum gases of light, as photon or polariton condensates, can be realized in low-dimensional, mostly two-dimensional experimental settings. We have determined the mechanical compressibility of a photon Bose-Einstein condensate realized in a box potential and revealed its equation of state [1].
In our experiment, a photon Bose-Einstein condensate is realized in a dye-solution-filled...
Traid anyons are indistinguishable particles in one dimension with topological exchange statistics that arise from quantizing the configuration space of indistinguishable particles in one dimension with three-body coincidences removed. For abelian traid anyons, when adjacent particles are exchanged, the state transforms as though they were either bosons or fermions. However, the Yang-Baxter...
We define a model of time-continuous measurement of position and momentum of a quantum particle. We assume that meters are arranged in a regular grid in phase space. Each of these detectors is characterized by a coherent state centered around a phase space location $(x_i,p_j)$ which defines a possible outcome of measurement. The post-measurement state is this coherent state. This way the...
I will present the results of our study on temperature sensing with finite-sized strongly correlated systems exhibiting quantum phase transitions. We use the quantum Fisher information (QFI) approach to quantify the sensitivity in the temperature estimation and apply a finite-size scaling framework to link this sensitivity to critical exponents of the system around critical points. We...
We study theoretically and experimentally the charge transport through a dissipative quantum point contact between two fermionic superfluids. Superconducting junctions are known to exhibit multiple Andreev reflections - a high-order cotunneling of a quasiparticle together with multiple Cooper pairs - which gives rise to a current at chemical potential biases below the energy gap. An...
In my contribution I will focus on the recent developments of the studies of dipolar gases and dipolar systems in lattices: these are described by extended or non-standard Hubbard model, exhibit strong correlations and lead to many exotic quantum phenomena. I will start with the first observation of the checkerboard state of indirect excitons in a 2D lattice [2] – a direct continuation of our...
Quantum vortices are generally thought of as funnel-like holes around which a quantum fluid exhibits a swirling flow. In this picture, vortex cores are empty regions where the superfluid density goes to zero.
Here we generalize this framework, by allowing the vortices to have a non-zero mass. The latter may arise for example due to atoms which are distinguishable from the ones composing the...
In 1935, Einstein, Podolsky, and Rosen (EPR) conceived a gedanken experiment which became a cornerstone of quantum technology and still challenges our understanding of reality and locality today. While the experiment has been realized with small quantum systems, a demonstration of the EPR paradox with massive many-particle systems remains an important challenge, as such systems are...
We have created a spatially homogeneous polariton condensate in thermal equilibrium. In-situ, non-destructive measurement of the coherence allows us to extract the quasicondensate fraction. These measurements reveal a striking 7/2 power law for the quasicondensate fraction overly nearly three orders of magnitude of density. The same power law is seen in simulations solving the generic...
Entanglement plays a crucial role in various quantum many-body phenomena, including the thermalization of isolated quantum systems and the information paradox of black holes. Notably, the second-order Rényi entropy (RE), a measure of entanglement, was successfully measured in the system of bosons in an optical lattice. Motivated by this experiment, we investigate the time evolution of the...
In recent years, our group has created homogeneous ultracold Fermi gases in two-dimensional and three-dimensional box potentials. Using Bragg spectroscopy we have determined the dynamic structure factor of spin-balanced superfluids in the BEC-BCS crossover and extracted both the superfluid gap and the critical velocity [1-2]. By directly comparing 2D and 3D superfluids we could directly...
Supersolids are an exotic phase of matter combining the contrasting characteristics of spontaneous continuous translational symmetry breaking in solids and frictionless flow in superfluids. Supersolids were predicted more than fifty years ago in the context of solid Helium [1, 2, 3] and were first observed in the context of ultracold atoms where cavity-mediated interactions [4, 5], dipolar...
Metastability is ubiquitous in nature and is observed through the crossing of an energy barrier toward a configuration of lower energy as, for example, in chemical processes or electron field ionization. In classical many-body systems, metastability naturally emerges in the presence of a first-order phase transition and finds a prototypical example in supercooled vapour. In the last decades,...
Geometrical frustration in strongly correlated systems can give rise to intriguing ordered states such as quantum spin liquids. In this work, we report on recent experimental progress in Fermi gas microscopy demonstrating emergent magnetic states in a Hubbard model with controllable frustration and doping. Using an optical lattice continuously tunable from a square to a triangular geometry, we...
I will discuss a "helical" superfluid, a nonzero-momentum condensate realized by frustrated bosonic on e.g., a honeycomb lattice. At a Bogoliubov level, such a novel state exhibits "smectic" fluctuation that are qualitatively stronger than that of a conventional superfluid. We develop a phase diagram and compute a variety of its physical properties, including the spectrum, structure factor,...
We present results regarding two topics. First, we explore magnetic polarons formed by holes hopping in an anti-ferromagnetic background in a lattice. We develop a non-perturbative theory both for the equilibrium and the non-equilibrium properties and find excellent agreement with experimental results, which is remarkable for a strongly interacting non-equilibrium many-body problem. We end by...
The nature of the flow between two superfluids, as in the Josephson and fountain effects, is often understood in terms of reversible flow carried by an entropy-free, macroscopic wavefunction. While this wavefunction is responsible for many intriguing properties of superfluids and
superconductors, its interplay with excitations in non-equilibrium situations is more subtle and less understood....
Atomic Bose-Einstein condensates represent a controllable quantum many-body playground, in which the degree of coherence and non-equilibrium coupling between coherent (condensed) and incoherent (thermal) components can be tuned by various parameters -- with typical experiments in inhomogeneous traps featuring a centrally-located condensate, surrounded by a thermal cloud, with the two...
Exact solutions for quantum many-body systems are rare but provide valuable insights for the description of universal phenomena. Recently, specific solutions of the Bethe ansatz equations for 1D anisotropic Heisenberg model were found that can carry macroscopic momentum yet no energy on top of the ferromagnetically "vacuum" state, dubbed phantom Bethe states. Consequently, spin helix at...
Verifying quantum simulators by learning the Hamiltonian is essential for future applications. Recently, sample-efficient Hamiltonian learning (HL) methods were developed for lattice systems, realizable with neutral atoms, trapped ions, or superconducting qubits. These methods rely on constraining coupling parameters in a local Hamiltonian ansatz by exact relations among local correlation...
Many of the breakthroughs in quantum science and technology rely on engineering strong Hamiltonian interactions between quantum systems. Typically, strong coupling relies on short-range forces or on placing the systems in high-quality electromagnetic resonators, which restricts the range of the coupling to short distances. We show how a loop of laser light can generate Hamiltonian coupling...
We report on a family of Bose-Hubbard diamond necklaces with $n$ central sites that exhibit quantum local Hilbert space
fragmentation [1]. Such models possess a single-particle spectrum with a flat band, which is composed of compact localized states (CLSs) that occupy the up and down sites of each diamond. Due to the presence of these CLSs, when adding more bosons with on-site interactions,...
The amplitude mode is a fundamental phenomenon that emerges from a broken continuous symmetry. In the framework of Ginzburg-Landau theory, this corresponds to an oscillation of the complex order parameter $\Delta$, which characterizes the long-range order of superfluids and superconductors. Typically, this mode is unstable and decays rapidly into pair-breaking excitations that exist within a...
Solitons are a hallmark feature of nonlinear dynamics. By balancing dispersion with interactions, solitons acquire a persistent nature that makes them observable in many important nonlinear systems. A variety of solitons have been considered in physical realizations including BECs, water tanks, optical fibers, plasmas, magnetic materials and more, making their study a central part of...
I will present several examples of nonergodic dynamics in strongly interacting systems in the presence of the disorder. Those will include (1D) dipolar models, tilted lattices as well as disordered cases.
The first model considered are dipolar bosons in a 1D lattice. By tailoring the transversal confinement one may modify the tail of interactions that profoundly affects the dynamics for...
In recent years, methods for automatic recognition of phase diagrams of quantum systems have gained large interest in the community: Among others, machine learning analysis of the entanglement spectrum has proven to be a promising route. Here, we discuss the possibility of using an experimentally readily accessible proxy, namely the number probability distribution that characterizes...
Important properties of complex quantum many-body systems and their phase diagrams can often already be inferred from the impurity limit. The Bose polaron problem describing an impurity atom immersed in a BEC is a paradigmatic example. However, its description at strong coupling is challenging due to the intricate competition between the emergent impurity-mediated attraction between the bosons...
The concept of a topological 'Thouless' pump involves the quantised motion of particles in response to a slow, cyclic modulation of external control parameters. Similar to the quantum Hall effect, the Thouless pump is of fundamental interest in physics because it links physically measurable quantities, such as particle currents, to geometric properties of the experimental system, whose...
Ultracold atoms in optical lattices represent an outstanding tool to create and study quantum many-body systems. Combining these lattice systems with the properties of alkaline-earth atoms such as strontium gives rise to exciting research directions. On one hand, sub-wavelength arrays of bosonic strontium exhibit strong cooperative effects in atom-photon scattering, and constitute rich...
On this poster, I present two recent studies on cold-atom dynamics.
Firstly, I will present our proposal to utilize cavity-BEC systems as a rotational sensor, see Ref. [1]. The atoms are set up in an array of Bose-Einstein condensates, and coupled to a single light mode of an optical cavity. The photon emission from the cavity indicates changes in the rotation frequency in real time, which...
I. Knottnerus1, 2, 3, Y.C. Tseng1,2, A. Urech1,2, D. Janse van Rensburg3, R. van Herk3, M. Venderbosch3, Z. Guo3, E. Vredenbregt3, S. Kokkelmans3, R. Spreeuw1,2,
F. Schreck1,2
1University of Amsterdam, Amsterdam
2QuSoft,...
Quasicrystals, a fascinating class of materials with long-range but nonperiodic order, exhibit fascinating properties due to their unique position at the crossroads of long-range-ordered and disordered systems. These include remarkable localization and fractal properties. While such properties are well known for single particles, the strongly-correlated regime remains largely unexplored....
In the last two years, exciting progresses on Bose-Einstein condensations (BEC) of molecules with bosonic atoms have been made. The Chicago group led by Chin has reported the achievement of the BEC of the G-wave Feshbach Cs molecules [1], and its ``super-chemistry”[2]. The Columbia group led by Will has created an ultra-cold gas of Na-Cs ground state molecules closed to BEC [3]. In this talk,...
I will present new strategies for engineering gauge theories with atomic platforms. First, I will illustrate the concept of encoding, eliminating partially or completely the gauge degrees of freedom by solving the local conservation laws of gauge theories. Then, I will show how to employ it to enable the realization of 1) topological gauge theories like chiral BF and Chern-Simons theories...
A significant fraction of topological materials has been characterized using symmetry requirements of wave functions. The past three years, however, have witnessed the rise of novel multi-gap dependent topological states, the properties of which go beyond these approaches and are yet to be fully explored. While such systems are thus of active interest already in static settings, most physical...
Cold atom platforms with single particle/spin detection and control offer fascinating opportunities for emerging quantum technologies.
Among quantum simulators atoms trapped in programmable optical tweezer arrays and excited to Rydberg states are nearly ideal systems to study quantum spin models. The short cycle time typically below one second makes modern protocols developed to characterize...
A current challenge in quantum gases is to produce trapped clouds of ultracold ground-state molecules having both an electric and a magnetic dipole moment. These would form a novel platform for investigations of few- and many-body physics, quantum simulation, quantum information and quantum-controlled chemistry. A promising route to achieve this is to combine ultracold alkali and closed-shell...
Ensemble of Rydberg atoms are a unique platform for quantum simulation and quantum computation because of their special properties [1,2]. In our research group, we are developing a novel approach for Rydberg-based quantum simulations and computations, where we use broadband pulsed lasers to excite 87Rb atoms, in Bose-Einstein condensates (BEC), Mott-Insulator (MI) lattice and optical tweezers,...
In 1961, I was a graduate student at Harvard when Gross and Pitaevskii published their time-dependent nonlinear Schroedinger equation. The GP equation describes quantized vortices with a core determined by quantum mechanics. My Ph D thesis “Vortices in an imperfect Bose gas” explored various implications of the GP equation, although it gives only a crude description of superfluid helium. ...
The tunability of the interaction strength in ultracold gases using either optical lattices or a Feshbach resonance allows to realize many-body systems whose Hamiltonian is scale invariant. The origin and unique features of the associated continuous symmetry are discussed for the example of a two-component Fermi gas at infinite scattering length. Its superfluid state differs fundamentally...
Dipolar interactions are fundamentally different from the usual van der Waals forces in real gases. Besides its anisotropy the dipolar interaction is nonlocal and as such allows for self organized structure formation, like in many different fields of physics. Although the bosonic dipolar quantum liquid is very dilute, stable droplets and supersolids as well as honeycomb or labyrinth patterns...
Conventional topological insulators exhibit exotic gapless edge or surface states, as a result of non-trivial bulk topological properties. In periodically-driven systems the bulk-boundary correspondence is fundamentally modified and knowledge about conventional bulk topological invariants is insufficient. While ultracold atoms provide excellent settings for clean realizations of Floquet...
In this talk I will describe work in the Simon/Schuster collaboration exploring protocols to build and probe manybody states of light. Beginning with an overview of the analogy between photons in a lattice of cavities and electrons in solids, I will then focus in on our explorations of Hubbard physics in a quantum circuit, where we have demonstrated the ability to build crystals of light using...
We show that a significant quantum gain corresponding to squeezed or over-squeezed spin states can be obtained in multiparameter estimation by measuring the Hadamard coefficients of a 1D or 2D signal. The physical platform we consider consists of two-level atoms in an optical lattice in a squeezed-Mott configuration, or more generally by correlated spins distributed in spatially separated...
Ultracold atoms in optical lattices form a versatile and well-controlled experimental platform for quantum simulation of solid-state physics. With typical lattice constants below one micrometer, optical resolution of individual lattice sites remains, however, technologically demanding. Here, I will present an imaging approach where matter-wave optics magnifies the density distribution before...
We will discuss our recent results on how quantum geometry affects various physical observables. For flat bands, we show that superfluidity [1,2] as well as stability of a Bose-Einstein condensate [3] is solely given by quantum geometric effects, such as finite quantum metric (Fubini-Study metric). Examples of prominent flat band systems are the Lieb lattice, the saw-tooth ladder, and moire...
Spin-orbit coupled Bose-Einstein condensates, where the internal state of the atoms is linked to their momentum through optical coupling, are a flexible experimental platform to engineer synthetic quantum many-body systems. In my talk, I will present recent work where we have exploited the interplay of spin-orbit coupling and tunable interactions in potassium BECs to realize two unconventional...
Exchange-antisymmetric pair wavefunctions in fermionic systems hold the promise of new types of quantum simulations, topological quantum gates, and exotic few-body states. However, p-wave and other antisymmetric interactions are weak in naturally occurring systems, and their enhancement via Feshbach resonances in ultracold systems has been limited by three-body loss. Here we revisit p-wave...
The problem of a quantum impurity in a Fermi gas is fundamental in physics, with relevance ranging from atomic gases to doped semiconductors to neutron stars. I will discuss the behavior of impurities with internal spin states coupled by a continuous Rabi drive, a scenario that is readily realised in cold-atom experiments. I will show how this reveals quantum many-body phenomena such as the...
Hydrodynamic instabilities in classical fluids, often characterized by the exponential growth of a well-defined pattern, are encountered in many mundane situations: the development of ocean waves, the periodic array of water droplets in a spider web or the mushroom-like clouds resulting from volcano eruptions are all examples of such instabilities. Increasing our understanding of the...
Atoms are employed as highly sensitive sensors in a wide range of applications, including metrology, precision gravimetry, and magnetometry. Atom lasers offer a compelling platform for mapping fields due to their large sampling area, tunable accelerations, and high atomic sensitivity.
In our work, we have conducted a series of experiments investigating the interaction of atom lasers with...
We utilize the rapidly developing capabilities of atom tweezer arrays to advance the studies of quantum optics, open quantum mechanics, and cavity QED. Single atoms in optical tweezers are used as scanning-probe microscopes to map out the structure of optical cavity modes.
We demonstrate rapid, high-fidelity, mid-circuit readout of an atom tweezer array using cavity-enhanced optical...
Understanding many-body systems far-from equilibrium is an outstanding challenge in physics. It was proposed that such systems generically feature universal dynamic scaling while approaching non-thermal fixed points; the associated dynamical scaling exponents would provide a classification of the nonequilibrium phenomena analogously to the equilibrium universality classes. First evidence for...
First, I will discuss the new possibilities that bulk molecular Bose-Einstein condensates may open up for dipolar many-body physics in the near future. Building on our work on dipolar droplets and supersolids that form from weakly dipolar atoms, I will show how ultracold molecules and microwave shielding can provide fundamentally new insights into these exotic states of matter. Second, I will...
We experimentally realize various dynamical phases such as a dissipative discrete time crystal [1], dynamical bond density wave phase [2-4], and limit cycle phase [5]. Our setup consists of a Bose-Einstein condensate of $^{87}$Rb atoms overlaps with a single mode optical cavity. The key feature of the cavity is a very small field decay rate ($\kappa / 2\pi$ = 3.6kHz), which is in an order of...
We study quantum many-body dynamics after a quantum quench in systems of optical lattices loaded with ultracold Bose gases, which can be quantitatively described by the Bose-Hubbard model. We focus on two kinds of dynamics, namely, spreading of spatial correlations and non-ergodic dynamics associated with the Hilbert space fragmentation. For the former case, we start with a Mott-insulating...
Supersolidity is an exotic phase of quantum matter which combines the characteristics of a superfluid with the crystalline spatial structure of a solid, resulting from the spontaneous breaking of both $U(1)$ phase symmetry and translational invariance. In spin-orbit-coupled Bose-Einstein condensates (SOC BECs), a spatially modulated density profile in the form of stripes emerges from the...
Hydrodynamics provides a successful framework to effectively describe complex many-body phenomena by coarse graining over microscopic constituents yielding macroscopic quantities. The requirement on the number of averaged microscopic particles is an outstanding question in various fields, ranging from nuclear to high energy physics.
Here, we challenge this condition by using few strongly...
Recent experiments with ultracold atoms in tilted optical lattices demonstrated unconventional relaxation dynamics of far-from-equilibrium initial states. Instead of the conventional diffusive relaxation, excitations decay only subdiffusively in these systems or may even come to a full stop. Here, we discuss how these observations can be understood by emergent fracton constraints. These...
Engineering long-range interactions in cold-atom quantum simulators can lead to exotic quantum many-body behaviour, becoming and enabling tool in the simulation of relevant problems in condensed matter or quantum chemistry [1]. In addition to recent efforts with bosonic species [2,3], fermionic atoms in ultracold atomic mixtures can also act as mediators. This gives rise to long-range...
Although non-local interactions characterize a variety of experimental setups their full control remains challenging. In this talk I will discuss two novel schemes where non-local interactions can be engineered and naturally put into competition with geometrical frustration. The first scheme is based on Cesium atoms trapped in a one-dimensional optical lattice at the anti-magic wavelength....
One of the most important challenges for fermionic systems in optical lattices is the quest for low temperatures. Only at temperatures below a few percent of the Fermi temperature, correlation lengths become sizeable. This is the regime in which the system behaves highly collective, and where new quantum phases are expected to emerge. Despite significant progress in recent years, the required...
Ultracold polar molecules promise a wide range of exciting new opportunities for quantum information processing, quantum simulations, cold chemistry, and precision measurements. I will present how microwave (MW) shielding of ground-state NaK molecules stabilizes collisions allowing us to evaporate dipolar molecules in 3D to quantum degenerate temperatures of 0.36 times their Fermi temperature....
Our group is studying the unique features of lanthanide atoms, such as dysprosium, for molecular quantum science.
We are building a new apparatus for controlling ultracold reactions between dysprosium atoms and dimers using an optical cavity. We report on the realization of a MOT of dysprosium and how we plan to achieve a molecular BEC.
On the side, we are exploring the optical spectra of...
The Fermi polaron, a particle dressed by excitations of a fermionic medium, has been extensively studied in ultracold atomic gases. Recently, it was realised that the optical response of doped atomically thin semiconductors also corresponds to a quantum impurity problem, where excitons are introduced into an electronic medium. I will discuss three scenarios where we have recently used...
Mixtures of Bose-Einstein condensates offer situations where the usually dominant mean-field energy in weakly interacting systems can be reduced such that higher-order (for example beyond-mean-field) terms may play a dominant role in the equation of state. In this context, the case of coupled two-component $^{39}$K Bose-Einstein condensates is specifically addressed. First, large attractive...
In quantum mechanics, collisions between two particles are captured by an energy-dependent scattering matrix describing the transfer from an initial entrance state to an outgoing final state. The scattering matrix can be analytically extended to a plane of non-physical complex energies where, remarkably, poles of this continued S-matrix will be intimately related to scattering resonances of...
Kinetic frustration is opening a new paradigm in cold atomic systems, as it induces non-trivial magnetic and spin-charge correlations at temperature scales of the order of the tunneling strength. This phenomenon appears in the strongly interacting regime of doped Fermi- and Bose-Hubbard Hamiltonians in non-bipartite lattices, such as the two-dimensional triangular lattice, and bipartite...
Heat engines convert thermal energy into mechanical work both in the classical and quantum regimes. However, quantum theory offers genuine nonclassical forms of energy, different from heat, which so far have not been exploited in cyclic engines. We here experimentally realize a novel quantum many-body engine fuelled by the energy difference between fermionic and bosonic ensembles of ultracold...
For the past two decades harmonically trapped ultracold atomic gases have been used with great success to study fundamental many-body physics in flexible experimental settings. However, the resulting gas density inhomogeneity in those traps makes it challenging to study paradigmatic uniform-system physics (such as critical behavior near phase transitions) or complex quantum dynamics.
The...
We explore the interaction between two trapped ions mediated by a surrounding quantum degenerate Bose or Fermi gas. Using perturbation theory valid for weak atom-ion interaction, we show analytically that the interaction mediated by a Bose gas has a power-law behavior for large distances whereas it has a Yukawa form for intermediate distances. For a Fermi gas, the mediated interaction is given...
Weakly interacting quantum gases offer a very convenient platform for the study of superfluid dynamics. One of the many intringuing properties of superfluids is their behavior in the presence of an imposed rotation. At zero temperature, the ground state of the rotating gas supports a triangular vortex lattice, the vortex density being set by the rotation frequency. As temperature increases,...
For a thorough investigation of both elastic and inelastic three-body interactions, ranging from universal Efimov physics to non-univeral species-dependent collisions, one needs a three-body collision model that can handle all regimes of interaction strength. We developed a full three-body spin-dependent coupled-channels model in momentum space, with a very accurate expansion of the full...
Photon-mediated interactions between atoms coupled to an optical cavity are emerging as a powerful tool for engineering entangled states and many-body Hamiltonians. In a next-generation cavity QED (CQED) experiment currently approaching completion at LKB, we combine a strong-coupling fiber Fabry-Perot microcavity with state-of-the-art atomic tweezer techniques for single-atom addressing and...
I will discuss the presence of non-ergodic extended states in many-body interacting systems in disorder. Our preliminary calculations indicate that these novel states can be present in the one-dimensional Hubbard model with on-site disorder for two-component fermions. These calculations rely on exact diagonalization and are able to provide results only for fairly small systems, namely up to 24...
We envision a hybrid quantum network of individually trapped polar molecules interfaced with Rydberg atoms. The nodes of the network are single molecules, where information is stored. The links are Rydberg atoms which mediate strong, long-range interactions between nodes. This hybrid network leverages the long-lived internal states of molecules and the strong interactions provided by Rydberg...
We demonstrate that the one-axis twisting (OAT), a versatile method of creating nonclassical states of bosonic qubits, is a powerful source of many-body Bell correlations. We develop a fully analytical and universal treatment of the process, which allows us to identify the critical time at which the Bell correlations emerge and predict the depth of Bell correlations at all subsequent times....
I will present three of our latest results on atomic quantum gases with engineered dissipation. This includes a joint work with the group of Artur Widera, where we investigate a phase transition in time during the transient relaxation dynamics of an open quantum systems [1], concepts for controlled state preparation using quantum feedback control in atomic cavities [2], as well as ideas...
Strongly correlated fermionic matter is at the heart of many open questions in quantum science, ranging from electon-Volt scale problems in condensed matter physics to Giga-electon-Volt dynamics in heavy ion collisions. Ultracold fermionic atoms are a unique platform, where the dynamics of interacting fermions can be probed using time- and particle-resolved correlation measurements.
In...
Supersolidity has recently been discovered in ultra-cold dipolar Bose gases. This intriguing state of matter is characterized by the spontaneous and simultaneous breaking of phase and translational symmetry, resulting in the non-intuitive coexistence of superfluid and crystalline features.
One of the fundamental characteristics of superfluidity is the existence of quantized vortices....
Ultracold atoms in triangular optical lattices are a versatile platform to study strongly correlated systems in which exotic states of matter appear due to the interplay between charge and magnetic order. Large degeneracies in the many-body ground state of triangular lattices could result in a quantum spin liquid that has been numerically predicted to appear between the metallic and...
Central spin models, where a single spinful particle interacts with a spin environment, find wide application in quantum information technology and can be used to describe, e.g., the decoherence of a qubit over time. We propose a method of realizing an ultracold quantum simulator of a central spin model with XX (spin-exchanging) interactions. The proposed system consists of a single Rydberg...
Due to advances in ultracold gas experiments and the recent unexpected discovery of superconductivity in magic-angle twisted bilayer graphene and other moiré materials, much effort is currently being devoted to understand superconductors and superfluids in the strongly correlated regime characterized by electronic energy bands with very small, or even vanishing, bandwidth. According to...
Anyons are particles with exchange statistics that are neither bosonic nor fermionic, but that interpolate between these two limits. We realize a one-dimensional Anyon-Hubbard model (AHM) with ultracold Rubidium 87 atoms in an optical lattice. To engineer the desired Hamiltonian, we use a novel three-tone lattice amplitude modulation technique that allows us to tune the exchange phase of two...
Finite temperature damping of rotons in elongated Bose-condensed dipolar gases which are in the Thomas-Fermi regime in the tightly confined directions, is discussed. The presence of many branches of excitations which can participate in the damping process is shown to result in significant increase of the damping rate. It is found, however, that even rotons with energies close to the roton gap...
We study driven atomic Josephson junctions realized by coupling two two-dimensional atomic clouds with a tunneling barrier. By moving the barrier at a constant velocity, dc and ac Josephson regimes are characterized by a zero and nonzero atomic density difference across the junction respectively. Here, we monitor the dynamics resulting in the system when, in addition to the the above...
The demanding experimental access to the ultrafast dynamics of materials challenges our understanding of their electronic response to applied strong laser fields. In this work, we show that trapped ultracold atoms with highly controllable potentials can become an enabling tool to describe phenomena in a scenario where some effects are more easily accessible and twelve orders of magnitude...
Bright solitons in atomic Bose-Einstein condensates are strong candidates for high precision matter-wave interferometry, as their inherent stability against dispersion supports long interrogation times. An analog to a beam splitter is then a narrow potential barrier. A very narrow barrier is desirable for interferometric purposes, but in a typical realization using a blue-detuned optical...
We employ spectroscopic tools to study interactions and emergent order in an ultracold mixture of a Bose-Einstein Condensate (BEC) and spin-polarized Degenerate Fermi Gas (DFG). We characterized the effect of fermion-mediated interaction on the boson clock transition [1]. We now extend our work by tuning the fermion-mediated effect on the Bogoliubov excitation spectrum through a Feshbach...
Following a quick review of the existence of supersolid and melted supersolid phases (hexatic superfluids) in two-dimensional continuum dipolar boson systems [1], the emergence of supersolid phases of dipolar and spin-orbit coupled bosons in optical lattices is discussed. For dipolar systems, it is shown that the ground state phase diagram is very sensitive to the direction of an externally...
When s-wave scattering length diverges in the vicinity of Feshbach resonances the system of three particles exhibits bound states characterized by universal properties [1,2]. A well-known fact is that near a narrow Feshbach resonance the existence range of these states shrinks down as a function of the narrowness of the resonance. Empirically, however, this is not the case for bosonic lithium....
Degenerate quantum gases with strong permanent dipole moments are a robust platform for studying anisotropic and long-ranged phenomena in strongly correlated quantum systems [1]. When subjected to a rotating magnetic field, the resulting precession of the dipole moments of a magnetic dipolar Bose-Einstein condensate (dBEC) imparts angular momentum to the system. Due to the superfluidity of an...
General relativity predicts that the curvature of spacetime induces spin rotations on a parallel transported spinful particle. We have deployed Unruh's analogue gravity picture and have considered an ordinary quantised vortex as a charged particle embedded in a two-dimensional scalar Bose--Einstein condensate (BEC). We have shown, backed by direct numerical simulations, that the vortex in a...
The ground state of a rapidly rotating superfluid is familiar as a triangular lattice of quantised vortices filling the condensate. This lattice of vortices can be considered an emergent chiral vortex matter, defined by the vortex interaction energy, angular momentum, and vortex number. In this picture, a continuum of equilibrium states of vortex matter is accessible, provided there is...
Topological defects determine properties and structure of disparate out-of-equilibrium physical and biological matter over a wide range of scales, from planetary atmospheres, turbulent flow in hydrodynamic classical and quantum fluids, up to electrical signalling in excitable biological media [1]. In superfluids and superconductors, the motion of quantised vortices is associated with the onset...
In this talk, I will report our recent research progress with ultracold atoms trapped in optical lattices. Ultracold atoms in optical lattices hold promise for the creation of entangled states for quantum simulation and quantum computation.
In our experiment, we developed a novel setup of spin-dependent optical superlattices. We were able to generate, manipulate and detect the atomic spin...
The exploration of atomic fractional quantum Hall (FQH) states is now within reach in optical-lattice experiments. While bulk signatures have been observed in a system realizing the Hofstadter-Bose-Hubbard model in a box [Leonard et al., Nature 2023], how to access hallmark edge properties in this setting remains a central open question.
We propose and analyze a realistic scheme to extract...
