Session F02: Synthetic Quantum Many-Body Systems

Quantum simulation with bosonic atoms in optical lattices under the microscope

Quantum gas microscopy provides unique access to the properties of quantum many-body system in- and out-of-equilibrium. Site-resolved density snapshots provide access to the full counting statistics of particle-number fluctuations in optical ladders, which we utilize in order to study the thermalization dynamics of hard-core bosons in quasi-1D systems, contrasting models with ballistic and chaotic dynamics. Using predictions from macroscopic fluctuation theory, we further extract diffusion constants from fluctuation growth in a far-from-equilibrium quench experiment. In addition, we demonstrate that optical superlattices can significantly expand the available toolbox by facilitating measurements of kinetic operators, such as kinetic energy or current. These operators can be measured and manipulated with single-bond resolution, which we demonstrate by locally rotating the measurement basis on isolated bonds using a digital-micromirror device. Moreover, single-shot readout provides information about full counting statistics and complex correlation functions. This paves the way for the implementation of efficient quantum state tomography and hybrid quantum computing protocols for itinerant particles on a lattice. We demonstrate the power of this technique by revealing the presence of local currents and current-current correlations in Hubbard models with artificial magnetic fields.   

Quantum Simulation of Electron Transfer Models with Trapped Ions

Laser-cooled trapped ions are a versatile platform for studying out-of-equilibrium dynamics of open quantum systems as they provide highly tunable unitary and non-unitary operations on both internal and external degrees of freedom. In this talk, I will first discuss our recent results [1] on the simulation of molecular electron transfer in a multi-species trapped-ion crystal. We use the hyperfine qubit of a 171Yb+ ion to simulate the electron degree of freedom and the optical qubit of a 172Yb+ ion to perform reservoir engineering on a collective mode encoding a reaction coordinate. This setting allows us to realize a paradigmatic model of molecular electron transfer where we can precisely and independently control the donor-acceptor gap, the electronic and the spin-phonon coupling, and the bath properties. We study the electron transfer dynamics in the nonperturbative regime where there is no clear hierarchy among the energy scales in the model, as it often occurs in biochemical systems [2,3]. I will also show our progress in the construction of a trapped-ion system based on a new monolithic 3D linear trap. Thanks to a combination of laser writing and etching, this trap combines the repeatability and modularity of microfabricated chip traps with the typical advantages of 3D traps, such as eV-deep trapping potentials, robustness to stray fields, larger ion-electrode distance, as well as wider and multi-directional optical access.

[1] V. So, M.D. Suganthi, et al., in preparation, (2024)

[2] D. J. Gorman et al., PRX 8, 011038 (2018)

[3] F. Schlawin, M. Gessner, et al., PRXQ, 2, 010314 (2021)   

Many-level Rydberg atoms: strongly correlated dynamics in a synthetic dimension

The last decade has seen tremendous advances in the control and manipulation of laser-trapped arrays of neutral atoms. The manipulation of Rydberg atoms in such arrays has led to great advances in the realms of analog quantum simulation and digital quantum computation. Here we describe how the simple addition of engineered microwave drives to such arrays can lead to a wealth of new few- and many-body phenomena. We describe a set of nascent experiments exploring dynamics of interacting Rydberg atoms along a synthetic (internal state) dimension, touching on interaction-driven phenomena relevant to topology, artificial gauge fields, and disorder-driven localization phenomena. Such microwave manipulation opens up new directions for exploring complex, driven quantum matter and exotic many-body dynamics.   

Exotic localization in driven cold-atom quasicrystals

Degenerate gases in modulated bichromatic lattices are a flexible testbed for the experimental study of driven quantum quasicrystals, in which the interplay of driving and pseudo-disorder gives rise to a variety of unusual transport phenomena. I will discuss results from a sequence of recent cold-atom experiments in this area, highlighting data on extended critical phases and the interplay between dynamical localization and Anderson localization, as well as a mapping to integer quantum Hall matter illuminated by light of arbitrary polarization.