The role of quantum coherence in energy fluctuations

TL;DR

This paper introduces a protocol to measure how quantum coherence influences energy fluctuations in open quantum systems, demonstrated experimentally on IBM's superconducting qubits.

Contribution

It proposes the end-point-measurement scheme to preserve quantum coherence effects in energy fluctuation measurements, a novel approach in quantum thermodynamics.

Findings

Quantum coherence affects energy fluctuation statistics.

The protocol successfully captures coherence effects experimentally.

Energy measurement uncertainties are managed without losing coherence information.

Abstract

We discuss the role of quantum coherence in the energy fluctuations of open quantum systems. To this aim, we introduce a protocol, to which we refer to as the end-point-measurement scheme, allowing to define the statistics of energy changes as a function of energy measurements performed only after the evolution of the initial state. At the price of an additional uncertainty on the initial energies, this approach prevents the loss of initial quantum coherences and enables the estimation of their effects on energy fluctuations. We demonstrate our findings by running an experiment on the IBM Quantum Experience superconducting qubit platform.