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arXiv · 2108.08853

Breaking the limits of purification: Postselection enhances heat-bath algorithmic cooling

Aaron Z. Goldberg·Khabat Heshami
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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.

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Aaron Z. Goldberg, Khabat Heshami. 2021-08-19. Breaking the limits of purification: Postselection enhances heat-bath algorithmic cooling. https://doi.org/10.1088/2399-6528%2Facb414

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