Quantum multiplexing with optical coherent states

TL;DR

This paper introduces a quantum multiplexing method using optical coherent states, enabling multiple users to share quantum communication channels with a novel superposition-based encoding.

Contribution

It presents a new quantum multiple access technique utilizing optical coherent states, including the design of quantum multiplexers and demultiplexers, expanding quantum communication capabilities.

Findings

Supports multiple users beyond traditional limits

Uses superposition of coherent states for encoding

Provides optical circuit designs for quantum multiplexing

Abstract

In this paper, we propose a novel quantum multiple access technique based on optical coherent states. The information of several coherent state optical qubits is combined into a single qudit, which is the superposition of almost orthogonal coherent states. The original information is encoded into a new Hilbert space with the help of a quantum multiplexer (QMUX) and then recovered at the other end with a quantum demultiplexer (QDEMUX). We introduce the optical tools that complete the coherence state quantum computation model and give the desired circuits. The proposed system can admit a number of users above the optimal limit at the cost of a degradation of the transmitted data. In this and some other aspects, it can be regarded as a quantum analogue of classical Code Division Multiple Access techniques.