There’s a quantum version of the 'hot water freezes faster' effect where hot quantum states reach their goal first.
March 19, 2026
Original Paper
Geometry and restoration of the quantum Mpemba effect beyond weak-coupling regime in the spin-boson model
arXiv · 2603.17565
The Takeaway
The Mpemba effect is a counterintuitive phenomenon where hot water can freeze faster than cold water. This study proves that a similar effect exists in the quantum world, showing that the specific geometry of a quantum system's energy allows it to take a 'shortcut' to relaxation that colder systems cannot access.
From the abstract
Understanding relaxation dynamics in open quantum systems is a central problem in nonequilibrium quantum physics. Here we investigate the quantum Mpemba effect in the spin-boson model. In the weak-coupling Markovian regime we show that the occurrence of the effect strongly depends on the choice of distance measure at low temperature: while it appears in the trace distance, it can disappear in the quantum relative entropy. Going beyond the weak-coupling approximation, numerically exact simulation