Thermodynamic uncertainty relations for coherently driven open quantum systems

TL;DR

This paper investigates how quantum coherence can reduce the thermodynamic cost of suppressing current fluctuations in open quantum systems, surpassing classical bounds and guiding the design of efficient quantum thermal machines.

Contribution

It demonstrates that quantum coherence can lower the thermodynamic cost of reducing fluctuations below classical limits in open quantum systems.

Findings

Quantum coherence reduces the thermodynamic cost below classical bounds.

The cost of fluctuation suppression can be arbitrarily small with many degrees of freedom.

Guidelines for designing high-precision quantum thermal machines.

Abstract

In classical Markov jump processes, current fluctuations can only be reduced at the cost of increased dissipation. To explore how quantum effects influence this trade-off, we analyze the uncertainty of steady-state currents in Markovian open quantum systems. We first consider three instructive examples and then systematically minimize the product of uncertainty and entropy production for small open quantum systems. As our main result, we find that the thermodynamic cost of reducing fluctuations can be lowered below the classical bound by coherence. We conjecture that this cost can be made arbitrarily small in quantum systems with sufficiently many degrees of freedom. Our results thereby provide a general guideline for the design of thermal machines in the quantum regime that operate with high thermodynamic precision, meaning low dissipation and small fluctuations around average values.