Mpemba effects in quantum complexity
Phys. Rev. B 114, 074310 – Published 25 August, 2026
DOI: https://doi.org/10.1103/tyw6-pjp6
Abstract
The Mpemba effect, a system farther from equilibrium relaxing faster, has been demonstrated for thermodynamic and symmetry-based quantities in classical, open-quantum, and isolated many-body systems. Whether the same phenomenology extends to quantum resources connected to computational complexity remains unexplored. Here, we investigate the relaxation of coherence, imaginarity, fermionic non-Gaussianity, and magic in subsystems of closed quantum systems evolved under random circuits composed of free gates. We find that coherence and imaginarity display the quantum Mpemba effect (QME) for tilted product states, while non-Gaussianity and magic do not. All four resources exhibit the quantum Pontus-Mpemba effect: a resourceful preheating stage accelerates the subsequent free relaxation. A spectral analysis reveals that the QME is controlled by the overlap of the initial state with the slowest decay mode of the effective Liouvillian, and that generic preheating suppresses this overlap. These results demonstrate that Mpemba physics is not restricted to thermodynamic or symmetry observables, but constitutes a general feature of quantum resource dissipation in complexity-relevant settings.
