The inverse Mpemba effect demonstrated on a single trapped ion qubit

TL;DR

This paper demonstrates a quantum analog of the inverse Mpemba effect on a single trapped ion qubit, showing that a colder quantum system can reach higher temperatures faster due to quantum coherence and interference effects.

Contribution

It introduces and experimentally demonstrates the inverse Mpemba effect in a quantum system, highlighting the role of coherence in anomalous thermal relaxation.

Findings

Cold qubits heat up faster than hot qubits in the quantum regime

The effect is exponential and occurs only in coherent quantum systems

Experimental validation on a single trapped ion qubit

Abstract

The Mpemba effect is a counter-intuitive phenomena in which a hot system reaches a cold temperature faster than a colder system, under otherwise identical conditions. Here we propose a quantum analog of the Mpemba effect, on the simplest quantum system, a qubit. Specifically, we show it exhibits an inverse effect, in which a cold qubit reaches a hot temperature faster than a hot qubit. Furthermore, in our system a cold qubit can heat up exponentially faster, manifesting the strong version of the effect. This occurs only for sufficiently coherent systems, making this effect quantum mechanical, i.e. due to interference effects. We experimentally demonstrate our findings on a single $^{88}\text{Sr}^+$ trapped ion qubit. The existence of this anomalous relaxation effect in simple quantum systems reveals its fundamentality, and may have a role in designing and operating quantum information processing devices.