Quantum Mpemba Effect: Chaos Orders Itself Faster express
Hot water sometimes freezes faster than cold — this is the Mpemba effect. In the quantum world, it’s even more astonishing: a system bubbling with disorder (with high entropy) can settle incredibly faster than one that is almost calm.
The solution lies in islands of silence within any system — regions untouched by the destructive noise of the environment.
The larger the system, the more such regions exist, and the calming cascades like an avalanche. A mathematical model confirmed that the speed grows exponentially: large structures seem to sweep out disorder with acceleration.
The discovery not only explains the paradox but also provides a key to ultra-stable quantum computers: instead of fighting noise, we can harness its rapid neutralization.
Original abstract
as written by the authors arXiv:2512.13509
In recent years, the quantum Mpemba effect (QME), which occurs when an out-of-equilibrium system reaches equilibrium faster than another that is closer to equilibrium, has attracted significant attention from the scientific community as an intriguing and counterintuitive phenomenon. It generalizes its classical counterpart by extending the concept beyond temperature equilibration. This paper approaches the QME in Markovian open quantum systems from different perspectives. First, we propose a physical mechanism based on decoherence-free subspaces. Second, we show that an exponential enhancement of the decay rate toward equilibrium, scaling with system size, can be obtained, leading to an extreme version of the phenomenon in Markovian open quantum systems. Third, we study the strong Mpemba effect through the unravelings of Davies maps, revealing subtleties in the choice of figures of merit used to identify the QME. Finally, we propose a microscopic model to gain deeper insight into bath dynamics in this context.
Entropy isn't just a measure of chaos: black holes in the Universe possess the maximum possible entropy.