Enhancing dissipative cat-state generation via nonequilibrium pump fields

TL;DR

This paper introduces a nonequilibrium pump method to significantly speed up and improve the robustness of dissipative cat-state generation, overcoming limitations of traditional equilibrium-based approaches.

Contribution

It demonstrates that removing the equilibrium requirement via a synchronous pump enhances cat-state generation speed and robustness, with practical implementation strategies.

Findings

Generation speed increased by one order of magnitude.

Enhanced robustness to single-photon loss.

Feasible implementation in time-multiplexed and standing mode systems.

Abstract

Cat states, which were initially proposed to manifest macroscopic superpositions, play an outstanding role in fundamental aspects of quantum dynamics. In addition, they have potential applications in quantum computation and quantum sensing. However, cat states are vulnerable to dissipation, which puts the focus of cat-state generation on higher speed and increased robustness. Dissipative cat-state generation is a common approach based on the nonlinear coupling between a lossy pump field and a half-frequency signal field. In such an approach, the pump field is usually kept in equilibrium, which limits the cat-state generation. We show that the equilibrium requirement can be removed by leveraging a synchronous pump method. In this nonequilibrium regime, the speed of the cat-state generation can be increased by one order of magnitude, and the robustness to single-photon loss can be enhanced. The realization of synchronous pumps is discussed for both time-multiplexed systems and standing modes.