Measurement Induced Synthesis of Coherent Quantum Batteries

TL;DR

This paper introduces a measurement-based method to synthesize a large coherent quantum battery from multiple two-level systems, leveraging environmental coherence and measurement strategies to enhance energy and coherence simultaneously.

Contribution

It proposes a novel measurement-induced synthesis process for creating large coherent quantum batteries from steady-state autonomous coherence.

Findings

Measurement process acts as a Maxwell demon for coherence and energy

Numerical optimization demonstrates efficiency of synthesis strategies

Feasible repeat-until-success protocol for quantum battery assembly

Abstract

Quantum coherence represented by a superposition of energy eigenstates is, together with energy, an important resource for quantum technology and thermodynamics. Energy and quantum coherence however, can be complementary. The increase of energy can reduce quantum coherence and vice versa. Recently, it was realized that steady-state quantum coherence could be autonomously harnessed from a cold environment. We propose a conditional synthesis of $N$ independent two-level systems (TLS) with partial quantum coherence obtained from an environment to one coherent system using a measurement able to increase both energy and coherence simultaneously. The measurement process acts here as a Maxwell demon synthesizing the coherent energy of individual TLS to one large coherent quantum battery. The measurement process described by POVM elements is diagonal in energy representation and, therefore, it does not project on states with quantum coherence at all. We discuss various strategies and their efficiency to reach large coherent energy of the battery. After numerical optimization and proof-of-principle tests, it opens way to feasible repeat-until-success synthesis of coherent quantum batteries from steady-state autonomous coherence.