Realizing a quantum Maxwell’s demon with superconducting circuits
Thermodynamics is a field of physics that describes quantities such as heat and work and their relationship to entropy and temperature. Originally developed as a theory to optimize the efficiency of heat engines, two extensions of thermodynamics in the last century advanced the theory to the point at which quantum mechanics should be incorporated. First, the role of information in thermodynamics, given by Shannon, Jaynes, and Landauer, makes strong connections between heat, entropy and information. Second, extensions of thermodynamics to the realm of microscopic systems in which fluctuations are significant allow the application of thermodynamics at the level of single trajectories of classical particles. Quantum mechanics requires both of these features as information and fluctuations are central to the behavior of quantum systems. The experimental control over single quantum systems that has been achieved in this century places us in a unique position to extend thermodynamics into the quantum regime. I will describe recent experiments where we harness tools from quantum information processing with superconducting qubits to quantify the role of information in a quantum realization of Maxwell’s demon.