Employing Circuit QED to Measure Nonequilibrium Work Fluctuations

TL;DR

This paper proposes and demonstrates a circuit QED-based interferometric method for measuring work fluctuations in driven quantum systems, including open and dissipative regimes, using qubit tomography.

Contribution

It introduces an extended implementation of the interferometric method employing two ancilla qubits for circuit QED systems, enabling experimental measurement of work statistics.

Findings

Method is feasible in strongly dissipative regimes.

Simulation confirms experimental viability.

Allows measurement of work in open quantum systems.

Abstract

We study an interferometric method for the measurement of the statistics of work performed on a driven quantum system, which has been put forward recently [Dorner et al., Phys. Rev. Lett. 110 230601 (2013), Mazzola et al., Phys. Rev. Lett. 110 230602 (2013)]. The method allows replacing two projective measurements of the energy of the driven system with qubit tomography of an ancilla that is appropriately coupled to it. We highlight that this method could be employed to obtain the work statistics of closed as well as open driven system, even in the strongly dissipative regime. We then illustrate an implementation of the method in a circuit QED set-up, which allows one to experimentally obtain the work statistics of a parametrically driven harmonic oscillator. Our implementation is an extension of the original method, in which two ancilla-qubits are employed and the work statistics is retrieved through two-qubit state tomography. Our simulations demonstrate the experimental feasibility.