OpenQMBP2023: New perspectives in the out-of-equilibrium dynamics of open many-body quantum systems

Simulating quantum transport on classical computers: Bridging the high- and low-temperature limits

20 juin 2023, 10:00

20m

Institut Pascal

Quantum Trajectories and Measurement Induced Phase Transitions

Orateur

Curt von Keyserlingk (KCL)

Description

Can we efficiently estimate transport coefficients (conductivities etc) in many-body quantum systems using classical computers? Drawing on lessons learned from studying scrambling and entanglement entropy dynamics in generic many-body systems, I propose an upper bound on the computational resources required to simulate transport at high temperatures: CPU time/memory $\sim e^{O(\log ({ϵ}^{-1}){)}^2}$, where $ϵ$ is the desired degree of precision. I'll describe a method (DAOE) achieving this bound. I'll explain why DAOE in its original form fails at low temperatures/extreme filling, and then propose an extension of it which shows encouraging signs of working in these limits.