Transport through a quantum critical system: A thermodynamically consistent approach

TL;DR

This paper presents a thermodynamically consistent method to analyze transport in quantum critical systems, capturing non-Markovian effects near quantum phase transitions, exemplified by the Lipkin-Meshkov-Glick model.

Contribution

It introduces a novel approach combining reaction coordinate mappings and polaron transforms for studying quantum transport near criticality.

Findings

Thermodynamically consistent reduced dynamics near quantum critical points.

Captures non-Markovian effects in transport.

Demonstrates quantum phase transition effects in heat transfer statistics.

Abstract

Currents through quantum systems may probe non-analyticities in quantum-critical many-body ground states. For a large class of dissipative quantum critical systems we show that it is possible to obtain the reduced system dynamics in the vicinity of quantum critical points in a thermodynamically consistent way, while capturing non-Markovian effects. We achieve this by combining reaction coordinate mappings with polaron transforms. Exemplarily, we consider the Lipkin-Meshkov-Glick model in a transport setup, where the quantum phase transition manifests itself in the heat transfer statistics.