Sequential projective measurements for channel decoding

TL;DR

This paper introduces a simple decoding method for quantum channels that uses only projective measurements and achieves channel capacity, providing an alternative proof of the classical capacity formula.

Contribution

It presents a novel decoding procedure based solely on projective measurements, simplifying the proof of the classical capacity of quantum channels.

Findings

Decoding procedure achieves channel capacity

Uses only projective measurements and yes/no tests

Provides an alternative proof of the Holevo bound

Abstract

We study the transmission of classical information in quantum channels. We present a decoding procedure that is very simple but still achieves the channel capacity. It is used to give an alternative straightforward proof that the classical capacity is given by the regularized Holevo bound. This procedure uses only projective measurements and is based on successive "yes"/"no" tests only.