Probing Quantum Interference Effects in the Work Distribution

TL;DR

This paper investigates how quantum coherence influences work distribution in quantum systems, proposing measurement schemes in circuit QED that reveal quantum interference effects and depend on detector states.

Contribution

It introduces two measurement schemes in circuit QED to observe quantum interference in work distribution, highlighting the role of detector states and coherence.

Findings

Work distribution depends on initial detector state and measurement choice

Quantum interference signatures are observable with proposed schemes

Minimal bosonic mode detector captures key quantum effects

Abstract

What is the role of coherence in determining the distribution of work done on a quantum system? We approach this question from an operational perspective and consider a setup in which the internal energy of a closed system is recorded by a quantum detector before and after the system is acted upon by an external drive. We find that the resulting work distribution depends on the initial state of the detector as well as on the choice of the final measurement. We consider two complementary measurement schemes, both of which show clear signatures of quantum interference. We specifically discuss how to implement these schemes in the circuit QED architecture, using an artificial atom as the system and a quantized mode of the electromagnetic field as the detector. Different measurement schemes can be realized by preparing the field either in a superposition of Fock states or in a coherent state and exploiting state-of-the art techniques for the characterization of microwave radiation at the quantum level. More generally, the single bosonic mode we utilize is arguably the minimal quantum detector capable of capturing the complementary aspects of the work distribution discussed here.