Universal cooling of quantum systems via randomized measurements
Abstract
Designing cooling protocols is believed to require knowledge of the system spectrum. In contrast, cooling in nature occurs whenever the system is coupled to a cold bath. How does nature know how to cool? A natural cold bath can be mimicked with a reservoir of "meter" qubits that are initialized in their ground state. We show that a quantum system can be cooled without knowledge of system details when system-meter interactions and meter splittings are chosen randomly. For sufficiently small interaction strengths and long interaction times, the protocol ensures that resonant energy-exchange processes, leading to cooling, dominate over heating. Effectively, the dynamics is then captured by the rotating-wave approximation, which we identify as the basic mechanism for robust and scalable cooling of complex quantum systems through generic, structure-independent protocols. This offers a versatile universal framework for controlling quantum matter far from equilibrium, in particular, for quantum computing and simulation.
Keywords
Cite
@article{arxiv.2506.11964,
title = {Universal cooling of quantum systems via randomized measurements},
author = {Josias Langbehn and George Mouloudakis and Emma King and Raphaël Menu and Igor Gornyi and Giovanna Morigi and Yuval Gefen and Christiane P. Koch},
journal= {arXiv preprint arXiv:2506.11964},
year = {2026}
}