Quantifying dynamical magic with completely stabilizer preserving operations as free

TL;DR

This paper extends the resource theory of magic to quantum channels using completely stabilizer preserving operations, introducing measures, conditions, and algorithms for quantifying, converting, and simulating quantum channel magic efficiently.

Contribution

It introduces a channel-based resource theory of magic with new measures, analytical conversion conditions, and an efficient classical simulation algorithm.

Findings

Quantifies channel magic using generalized robustness and min relative entropy.

Provides linear programming conditions for qubit channel interconversion.

Develops a classical simulation algorithm with runtime linked to channel magic.

Abstract

In this paper, we extend the resource theory of magic to the channel case by considering completely stabilizer preserving operations (CSPOs) as free. We introduce and characterize the set of CSPO preserving and completely CSPO preserving superchannels. We quantify the magic of quantum channels by extending the generalized robustness and the min relative entropy of magic from the state to the channel domain and show that they bound the single-shot dynamical magic cost and distillation. We also provide analytical conditions for qubit interconversion under CSPOs and show that it is a linear programming feasibility problem and hence can be efficiently solved. Lastly, we give a classical simulation algorithm whose runtime is related to the generalized robustness of magic for channels. Our algorithm depends on some pre-defined precision, and if there is no bound on the desired precision then it achieves a constant runtime.