Qubit magic-breaking channels

TL;DR

This paper introduces and characterizes quantum channels called magic-breaking channels that destroy the non-stabilizerness of states, thereby rendering them useless for universal quantum computation, with comprehensive criteria for qubit channels.

Contribution

It provides necessary and sufficient conditions for qubit channels to be magic-breaking, along with algorithms and criteria for various classes and tensor products, advancing the understanding of magic resource theory.

Findings

Criteria for qubit channels to be magic-breaking

Algorithm for identifying magic-breaking channels

Implications for magic preservability in quantum dynamics

Abstract

We develop a notion of quantum channels that can make states useless for universal quantum computation by destroying their magic (non-stabilizerness) - we refer to them as magic-breaking channels. We establish the properties of these channels in arbitrary dimensions. We prove the necessary and sufficient criteria for qubit channels to be magic-breaking and present an algorithm for determining the same. Moreover, we provide compact criteria in terms of the parameters for several classes of qubit channels to be magic-breaking under various post-processing operations. Further, we investigate the necessary and sufficient conditions for the tensor product of multiple qubit channels to be magic-breaking. We establish implications of the same for the dynamical resource theory of magic preservability.