Autonomous dissipative Maxwell's demon in a diamond spin qutrit

TL;DR

This paper demonstrates an autonomous Maxwell demon using a diamond spin qutrit, controlling dissipative dynamics and measurements to explore quantum thermodynamics and energy fluctuations.

Contribution

It experimentally realizes an autonomous feedback process in a spin qutrit, integrating coherent and dissipative control with tunable strength.

Findings

Successful implementation of an autonomous Maxwell demon in a diamond NV center

Quantification of energy exchange fluctuations using a generalized Sagawa-Ueda-Tasaki relation

Potential applications in quantum sensing and thermodynamic devices

Abstract

Engineered dynamical maps combining coherent and dissipative transformations of quantum states with quantum measurements, have demonstrated a number of technological applications, and promise to be a crucial tool in quantum thermodynamic processes. Here, we exploit the control on the effective open spin qutrit dynamics of an NV center, to experimentally realize an autonomous feedback process (Maxwell demon) with tunable dissipative strength. The feedback is enabled by random measurement events that condition the subsequent dissipative evolution of the qutrit. The efficacy of the autonomous Maxwell demon is quantified by experimentally characterizing the fluctuations of the energy exchanged by the system with the environment by means of a generalized Sagawa-Ueda-Tasaki relation for dissipative dynamics. This opens the way to the implementation of a new class of Maxwell demons, which could be useful for quantum sensing and quantum thermodynamic devices.