Canonical Quantum Mpemba Effect in a Dissipative Qubit

The Mpemba effect, where a hotter system cools faster than a colder one under otherwise identical conditions, has been extensively studied in classical systems. In this work, we present the quantum analogue of the Mpemba effect using a dissipative qubit, which is referred to as the canonical quantum Mpemba effect. We demonstrate that, under identical conditions, the relaxation dynamics of a qubit initialized in a thermal state with a higher temperature can be exponentially faster than that of a colder thermal state. Strikingly, for a fixed Liouvillian, this acceleration can be selected solely by varying the initial temperature, rather than by applying a specially designed unitary transformation to the initial state. The existence and value of the critical temperature nevertheless depend on the system and dissipation parameters. The relaxation is characterized as an overall cooling process: the system evolves from a higher-temperature, higher-energy thermal state toward a steady state with a lower effective temperature and energy, mirroring its classical counterpart. Last, we propose a practical classical–quantum hybrid algorithmic quantum circuit to simulate the dissipative evolution of thermal states and validate its experimental feasibility using superconducting qubits.