Quantum Virtual Cooling

Author
Abstract
We propose a quantum-information-based scheme to reduce the temperature of quantum many-body systems and access regimes beyond the current capability of conventional cooling techniques. We show that collective measurements on multiple copies of a system at finite temperature can simulate measurements of the same system at a lower temperature. This idea is illustrated for the example of ultracold atoms in optical lattices, where controlled tunnel coupling and quantum gas microscopy can be naturally combined to realize the required collective measurements to access a lower, virtual temperature. Our protocol is experimentally implemented for a Bose-Hubbard model on up to 12 sites, and we successfully extract expectation values of observables at half the temperature of the physical system. Additionally, we present related techniques that enable the extraction of zero-temperature states directly.
Year of Publication
2019
Journal
Physical Review X
Volume
9
Date Published
2019-07
URL
https://journals.aps.org/prx/abstract/10.1103/PhysRevX.9.031013
DOI
10.1103/PhysRevX.9.031013
JILA PI
Journal Article