Analyzing the efficacy and work extraction of a quantum Maxwell’s demon

In a quantum Maxwell’s demon experiment, two major quantities are commonly investigated - the average work extraction〈W〉, and the efficacy γ which measures the violation of Jarzynski’s equality when extracted information and feedback is not accounted for. Here, we carefully analyze the relation between these two quantities, and find that they are not maximized simultaneously, requiring different feedback protocols. Furthermore, we investigate Maxwell’s demon protocols for higher dimensional Hilbert spaces finding even stronger violations of Jarzynski’s equality. Our study further reveals the thermodynamic implications of the exponentially large state space available in quantum systems.