Speaker
Description
We report on the development of a quantum simulation platform based on Rydberg-excited
⁴⁰Ca⁺ ions confined in a Penning trap [1,2]. The platform is designed to study long-time
quantum dynamics, collective behavior, and nonequilibrium phenomena in open many-body
systems on timescales far beyond those accessible with conventional trapped-ion simulators
[3].
Exciting ions to Rydberg states offers a distinct advantage for engineering spin interactions:
the resulting dipolar couplings between neighboring ions are up to two orders of magnitude
stronger than those achievable through standard laser coupling to vibrational modes [1,6].
Rydberg states' huge polarizability makes them sensitive to the oscillating confining field of a
Paul trap. This leads to mixing and broadening the Rydberg spectrum through Floquet
sidebands which is an unavoidable effect in Paul traps [8]. The Penning trap architecture
removes this obstacle entirely, as confinement is achieved through a static electric field
combined with a strong static magnetic field, eliminating micromotion associated Floquet
mixing, and is expected to support trapping lifetimes of up to several days in combination
with a cryogenic enclosure [7].
Microwave dressing of the Rydberg states is used to tune and control the resulting
dipole-dipole interactions, allowing state-dependent coupling strengths to be engineered
directly and enabling simulation of tailored spin models on a planar ion crystal with a high
degree of control [5].
The current developmental stage of the project focuses on the magnetic confinement,
achieved using an in-house permanent magnet Halbach array configuration [4]. This has
been fully assembled and characterized, with field simulations and Hall-probe
measurements at room temperature and liquid nitrogen temperatures confirming
homogeneity of around 2600 ppm across the ion trapping region.
References:
[1] A. Mokhberi et al., Adv. Atom. Mol. Opt. Phys. 69, 233–306 (2024)
[2] A. Polloreno et al., arXiv:2203.05196 (2022)
[3] C. Chen et al., Nature 616, 691 (2023)
[5] H. Bao et al., Europhys. Lett. 151, 55003 (2025)
[6] W. S. Martins et al., arXiv:2601.01626 (2026), in prep. for PRX
[7] J. Andrijauskas et al., Phys. Rev. Lett. 127, 203001 (2021)
[8] W. S. Martins, J. W. P. Wilkinson, M. Hennrich, I. Lesanovsky, Phys. Rev. A 111, 043106
(2025)