Breaking the limits of purification: Postselection enhances heat-bath algorithmic cooling
Abstract
Quantum technologies require pure states, which are often generated by extreme refrigeration. Heat-bath algorithmic cooling is the theoretically optimal refrigeration technique: it shuttles entropy from a multiparticle system to a thermal bath, thereby generating a quantum state with a high degree of purity. Here, we show how to surpass this hitherto-optimal technique by taking advantage of a single binary-outcome measurement. Our protocols can create arbitrary numbers of pure quantum states without any residual mixedness by using a recently discovered device known as a quantum switch to put two operations in superposition, with postselection certifying the complete purification.
Cite
@article{arxiv.2108.08853,
title = {Breaking the limits of purification: Postselection enhances heat-bath algorithmic cooling},
author = {Aaron Z. Goldberg and Khabat Heshami},
journal= {arXiv preprint arXiv:2108.08853},
year = {2023}
}
Comments
11 pages, 3 figures, 1 appendix; updated references; close to published version