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arXiv · 2302.07908

Linear optical logical Bell state measurements with optimal loss-tolerance threshold

Paul Hilaire·Yaron Castor·Edwin Barnes·Sophia E. Economou·Frédéric Grosshans
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Abstract

Quantum threshold theorems impose hard limits on the hardware capabilities to process quantum information. We derive tight and fundamental upper bounds to loss-tolerance thresholds in different linear-optical quantum information processing settings through an adversarial framework, taking into account the intrinsically probabilistic nature of linear optical Bell measurements. For logical Bell state measurements - ubiquitous operations in photonic quantum information - we demonstrate analytically that linear optics can achieve the fundamental loss threshold imposed by the no-cloning theorem even though, following the work of Lee et al., (Phys. Rev. A 100, 052303 (2019)), the constraint was widely assumed to be stricter. We spotlight the assumptions of the latter publication and find their bound holds for a logical Bell measurement built from adaptive physical linear-optical Bell measurements. We also give an explicit even stricter bound for non-adaptive Bell measurements.

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Paul Hilaire, Yaron Castor, Edwin Barnes, Sophia E. Economou, Frédéric Grosshans. 2023-02-15. Linear optical logical Bell state measurements with optimal loss-tolerance threshold. https://arxiv.org/abs/2302.07908

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