Entanglement can increase asymptotic rates of zero-error classical communication over classical channels

TL;DR

This paper demonstrates that shared entanglement can enhance the asymptotic zero-error classical communication capacity of certain channels, even reaching the channel's normal capacity, using examples based on exceptional root systems.

Contribution

It provides explicit examples showing entanglement increases asymptotic zero-error capacity, resolving an open question in quantum information theory.

Findings

Entanglement can increase zero-error capacity asymptotically.

Examples are based on exceptional root systems E7 and E8.

Entanglement can match the channel's normal capacity.

Abstract

It is known that the number of different classical messages which can be communicated with a single use of a classical channel with zero probability of decoding error can sometimes be increased by using entanglement shared between sender and receiver. It has been an open question to determine whether entanglement can ever increase the zero-error communication rates achievable in the limit of many channel uses. In this paper we show, by explicit examples, that entanglement can indeed increase asymptotic zero-error capacity, even to the extent that it is equal to the normal capacity of the channel. Interestingly, our examples are based on the exceptional simple root systems E7 and E8.