Abstract
We present a new method to measure the work performed on a driven quantum system and to sample its probability distribution . The method is based on a simple fact that remained unnoticed until now: Work on a quantum system can be measured by performing a generalized quantum measurement at a single time. Such measurement, which technically speaking is denoted as a positive operator valued measure reduces to an ordinary projective measurement on an enlarged system. This observation not only demystifies work measurement but also suggests a new quantum algorithm to efficiently sample the distribution . This can be used, in combination with fluctuation theorems, to estimate free energies of quantum states on a quantum computer.
- Received 23 July 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.250601
© 2014 American Physical Society
Synopsis
Work in the Quantum World
Published 18 December 2014
A new method of measuring work in a quantum-mechanical setting provides a way to evaluate the thermodynamics of small, fluctuating systems.
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