Group seminar at MPQ: Simulating Lattice Gauge Theories with Ultracold Atoms

May 16, 2023

Prof. Zhen-Sheng Yuan, University of Science and Technology of China
Group Seminar at MPQ lecture hall and zoom
Tuesday, May 16th, 9:00am (MEZ)

Abstract:

Gauge theories implement fundamental laws of physics by local symmetry constraints. For example, quantum electrodynamics and quantum chromodynamics are both based on gauge theories. However, the equations of gauge theories are usually hard to solve, forming exceptional challenges to supercomputer based numerical procedures. We intend to overcome the challenges by quantum simulation with ultracold atoms. We developed unique techniques of spin-dependent superlattices, microscopic imaging, and number-resolved detection. A new method of deep cooling in optical lattice is realized and a defect-free system is achieved for creating 1250 pairs of entangled atoms [1]. Thanks to these advances, we implemented a four-body ring-exchange Hamiltonian in plaquette lattices [2] and then a Schwinger model with a Hubbard model in deep lattice regime of a 71-site quantum simulator [3]. We observed the interaction and conversion between matter fields and gauge fields and verified Gauss’s law. Furthermore, we studied the thermalization properties of this lattice gauge theory [4,5]. Our quantum simulator can be used to study false vacuum decay, dynamical transitions related to the topological θ-angle and other features of gauge theories under extreme conditions.

[1] Bing Yang et al. Science, 369(6503):550–553, 2020.

[2] Han-Ning Dai et al. Nature Physics, 13(12):1195–1200, 2017.

[3] Bing Yang et al. Nature, 587(7834):392–396, 2020.

[4] Zhao-Yu Zhou et al. Science, 377(6603):311–314, 2022.

[5] Han-Yi Wang et al. arXiv:2210.17032.