Deterministic feedforward-based generation of large optical coherent-state superposition

TL;DR

This paper introduces a deterministic, feedforward protocol using qubit-mode dispersive coupling in cavity QED to generate large optical coherent-state superpositions, outperforming previous methods in fidelity and quantum properties.

Contribution

It presents a novel single-mode, feedforward approach for generating large optical superpositions, integrating QED with electro-optical techniques, and demonstrating improved performance over existing schemes.

Findings

Outperforms three-mode Gaussian-photon-number-resolving detector scheme in fidelity

Achieves enhanced quantum non-Gaussian phase-space properties

Proposes a feasible method to detect quantum interference via weak displacements

Abstract

Large optical coherent-state superpositions are essential to advance quantum sensing, quantum repeaters and error-correction codes. We propose a deterministic feedforward protocol employing qubit-mode dispersive coupling, currently available in cavity quantum electrodynamics (QED). We show this single-mode protocol to outperform the advanced three-mode Gaussian-photon-number-resolving detector scheme both in terms of average fidelity and quantum non-Gaussian phase-space properties, and propose sensitivity to weak displacements of interference fringes as a feasible and conclusive witness of quantum interference. This approach combining QED with electro-optical feedforward is extendable to tailored states for applications and other platforms.