Group seminar at MPQ and Zoom: 
Many-body delocalization on a two-dimensional superconducting quantum simulator
 

Zheng-Hang Sun, University of Augsburg, Germany
Group seminar at MPQ lecture hall and Zoom
Tuesday, 21 October, 09:00am (MEZ)
 

Quantum many-body systems with sufficiently strong disorder can exhibit a non-equilibrium phenomenon, known as the many-body localization (MBL), which is distinct from conventional thermalization. While the MBL regime has been extensively studied in one dimension, its existence in higher dimensions remains elusive, challenged by the avalanche instability. Because the problem is notoriously hard to address numerically, quantum simulation offers a promising route to its solution. In this report, we begin with a brief technical overview of superconducting qubits and a conceptual introduction to MBL. We then present a recent quantum simulation focusing on the stability of finite-size MBL regime in 2D based on both superconducting qubits. We observe that the decay of imbalance becomes more pronounced with increasing system sizes, scaling up from 21, 42 to 70 qubits, with a relatively large disorder strength, and for the first time, provide an evidence for the many-body delocalization in 2D disordered systems. Finally, we discuss future directions for addressing this problem, especially leveraging cold-atom quantum simulators.