Quantum typicality approach to energy flow between two spin-chain domains at different temperatures

TL;DR

This paper introduces a quantum typicality method to study energy flow between two spin-chain systems at different temperatures, effectively capturing steady-state energy currents across various models and temperature regimes.

Contribution

The paper extends quantum typicality techniques to low-temperature dynamics and validates the approach by accurately reproducing steady-state energy currents in multiple spin-chain models.

Findings

Agreement with analytical results for energy current

Effective simulation of low-temperature dynamics

Validation across different spin-chain models

Abstract

We discuss a quantum typicality approach to examine systems composed of two subsystems at different temperatures. While dynamical quantum typicality is usually used to simulate high-temperature dynamics, we also investigate low-temperature dynamics using the method. To test our method, we investigate the energy current between subsystems at different temperatures in various paradigmatic spin-1/2 chains, specifically the XX chain, the critical transverse-field Ising chain, and the XXZ chain. We compare our numerics to existing analytical results and find a convincing agreement for the energy current in the steady state for all considered models and temperatures.