Numerically exact open quantum system work statistics with process tensors

TL;DR

This paper introduces a process tensor framework for exactly calculating quantum work statistics in driven open quantum systems, revealing quantum signatures affecting thermodynamics and control in complex environments.

Contribution

It presents a novel, non-perturbative method to compute full work distributions, surpassing traditional approximations in non-equilibrium quantum thermodynamics.

Findings

Work distributions show quantum signatures missed by low-order moments.

Framework accurately characterizes energy fluctuations in complex quantum systems.

Application to Landauer erasure demonstrates impact on fidelity and thermodynamics.

Abstract

Accurately quantifying the thermodynamic work costs of quantum operations is essential for the continued development and optimisation of emerging quantum technologies. This present a significant challenge in regimes of rapid control within complex, non-equilibrium environments - conditions under which many contemporary quantum devices operate and conventional approximations break down. Here, we introduce a process tensor framework that enables the computation of the full numerically exact quantum work statistics of driven open quantum systems. We demonstrate the utility of our approach by applying it to a Landauer erasure protocol operating beyond the weak-coupling, Markovian, and slow-driving limits. The resulting work probability distributions reveal distinct quantum signatures that are missed by low-order moments yet significantly impact the erasure fidelity of the protocol. Our framework delivers non-perturbative accuracy and detail in characterising energy-exchange fluctuations in driven open quantum systems, establishing a powerful and versatile tool for exploring thermodynamics and control in the operating regimes of both near-term and future quantum devices.