Discrimination of two channels by adaptive methods and its application to quantum system

TL;DR

This paper investigates the limits of adaptive methods in discriminating two channels, showing that adaptivity does not enhance the exponential error rate, with applications to quantum state discrimination.

Contribution

It proves that adaptive input choices do not improve exponential error rates in channel discrimination across various settings, including quantum systems.

Findings

Adaptive choice does not improve exponential error rate in channel discrimination.

Results apply to quantum state discrimination.

Theoretical bounds established for adaptive methods.

Abstract

The optimal exponential error rate for adaptive discrimination of two channels is discussed. In this problem, adaptive choice of input signal is allowed. This problem is discussed in various settings. It is proved that adaptive choice does not improve the exponential error rate in these settings. These results are applied to quantum state discrimination.