Indirect Measurement for Optimal Quantum Communication Enhanced by Binary Non-standard Coherent States

TL;DR

This paper demonstrates that the improved Helstrom bound for quantum state discrimination can be achieved using orthogonal non-standard Schrödinger cat states and nearly attained through an experimentally feasible indirect measurement based on the Jaynes-Cummings model.

Contribution

It introduces a new measurement scheme using non-standard Schrödinger cat states and shows its effectiveness in approaching the Helstrom bound in quantum communication.

Findings

Projective measurement with orthogonal Schrödinger cat states achieves the improved Helstrom bound.

Numerical simulations show near-achievement of the bound via Jaynes-Cummings model-based indirect measurement.

Potential for experimental implementation of the proposed measurement scheme.

Abstract

It is well known that the Helstrom bound can be improved by generalizing the form of a coherent state. Thus, designing a quantum measurement achieving the improved Helstrom bound is important for novel quantum communication. In the present article, we analytically show that the improved Helstrom bound can be achieved by a projective measurement composed of orthogonal non-standard Schr\"{o}dinger cat states. Moreover, we numerically show that the improved Helstrom bound can be nearly achieved by an indirect measurement based on the Jaynes-Cummings model. As the Jaynes-Cummings model describes an interaction between a light and a two-level atom, we emphasize that the indirect measurement considered in this article has potential to be experimentally implemented.