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

Understand

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.
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