Incompatibility of quantum channels

Abstract

Two quantum channels are called compatible if they can be obtained as marginals from a single broadcasting channel; otherwise they are incompatible. We derive a characterization of the compatibility relation in terms of concatenation and conjugation, and we show that all pairs of sufficiently noisy quantum channels are compatible. The complement relation of incompatibility can be seen as a unifying aspect for many quantum features. We demonstrate that several phenomena, such as impossibility of universal broadcasting and unavoidable measurement disturbance, appear naturally in this framework.

References in corpus (5)

• The structure of degradable quantum channels
• Verifying the quantumness of a channel with an untrusted device
• All measurements in a probabilistic theory are compatible if and only if the state space is a simplex
• On quantum estimation, quantum cloning and finite quantum de Finetti theorems
• Game-theoretic characterization of antidegradable channels

Cited by in corpus (2)

• Conditions for the compatibility of channels in general probabilistic theory and their connection to steering and Bell nonlocality
• Noise-disturbance relation and the Galois connection of quantum measurements