Exploring non-ergodicity in lattice gauge theories with fermionic Yb

点击翻译按钮获取中文摘要

Gauge theories are essential for our understanding of nature and their properties provide exciting new opportunities for interdisciplinary research. Unfortunately, many fundamental properties, especially in the context of out-of-equilibrium dynamics, remain largely inaccessible with conventional numerical methods. Within this project we are going to perform quantum simulation of simplified lattice gauge theories (LGTs) using a new hybrid tweezer-lattice using Yb atoms in state-dependent optical lattices, which will offer high-resolution imaging and manipulation techniques provided by quantum gas microscopy. The main goal is to study non-ergodicity and out-of-equilibrium phenomena in U(1) LGTs coupled to matter. The implementation makes use of the formulation of LGTs in terms of quantum link models (QLMs), where the Hilbert space of the gauge field is truncated and finite. The simplest realization can be mapped to spin-1/2 operators, which in our case are represented by the two optical clock states of Yb. These two states also facilitate a convenient implementation of state-dependent potentials with far-detuned laser beams. With the help of local state-dependent addressing provided by tightly-focused optical tweezer beams, we are going to realize a lattice potential, where the dynamics is strongly constrained in order to fulfill Gauss’s law for the QLM. The dominant tunneling term is a correlated hopping process of two atoms, which can be mapped onto a U(1) QLM. The scheme does not require any laser-assisted tunneling or Raman coupling, which should enable long coherence times, as needed for the study of non-ergodic phenomena. The local addressing and observation techniques combined with high-precision spectroscopy on the optical clock transition facilitates the implementation of initial states that fulfill Gauss’s law. This opens the door to experimental studies of the predicted confinement-deconfinement transition in our model and to explore disorder-free localization in one-dimension, which may occur due to the local constraints imposed by Gauss’s law. Moreover, the experimental implementation is designed in order to study out-of-equilibrium phenomena in two dimensions, which we will start to investigate in strong collaboration with the theory groups of this proposed Research Unit towards the end of the first funding period.