Experimental Demonstration of a Maxwell's Demon Quantum Battery in a Superconducting Noisy Intermediate-Scale Quantum Processor

Entering the era of post-quantum supremacy has given one the ability to precisely control noisy intermediatescale quantum (NISQ) processors with multiqubits and extract valuable quantum many-body correlation resources for many distinct quantum applications. We here construct quantum many-body thermalized states on a 62-qubit superconducting quantum processor and use them to demonstrate the principle of Maxwell's demon. We further demonstrate the direct effect caused by Maxwell's demon on the charging process of a quantum battery (QB). We depicted the nonequilibrium transportation in our QB through measuring the dynamics of the Shannon entropy to explore its working conditions. Finally, we evaluate the information-to-work conversion by varying the readout fidelity to verify the validity of the Sagawa-Ueda equality within the NISQ processor environment and evaluate the qubit-environment interaction such as the measurement backaction. Our experiment suggests that the superconducting NISQ processor with appropriate error mitigation methods will be an ideal platform for studying quantum information thermodynamics through quantum many-body simulations.