All-optical generation of deterministic squeezed Schr\"odinger-cat states

TL;DR

This paper proposes an all-optical, deterministic method to generate squeezed Schrödinger-cat states using engineered dissipation, enabling high-speed state preparation and enhanced phase estimation near the Heisenberg limit.

Contribution

It introduces a novel all-optical scheme leveraging Fredkin-type interactions for deterministic squeezed Schrödinger-cat state generation, with tunable two-photon loss for faster preparation.

Findings

Effective degenerate three-wave mixing causes two-photon loss.

Quantum Fisher information reaches the Heisenberg limit for large photon numbers.

Method offers significant advantage in low-photon regimes for fragile systems.

Abstract

Quantum states are important resources and their preparations are essential prerequisites to all quantum technologies. However, they are extremely fragile due to the inevitable dissipations. Here, an all-optical generation of a deterministic squeezed Schr$\ddot{\mathrm{o}}$dinger-cat state based on dissipation is proposed. Our system is based on the Fredkin-type interaction between three optical modes, one of which is subject to coherent two-photon driving and the rest are coherent driving. We show that an effective degenerate three-wave mixing process can be engineered in our system, which can cause the simultaneous loss of two photons, resulting in the generation of a deterministic squeezed Schr$\ddot{\mathrm{o}}$dinger-cat state. More importantly, by controlling the driving fields in our system, the two-photon loss can be adjustable, which can accelerate the generation of squeezed Schr$\ddot{\mathrm{o}}$dinger-cat states. Besides, we exploit the squeezed Schr$\ddot{\mathrm{o}}$dinger-cat states to estimate the phase in the optical interferometer, and show that the quantum Fisher information about the phase can reach the Heisenberg limit in the limit of a large photon number. Meanwhile, it can have an order of magnitude factor improvement over the Heisenberg limit in the low-photon-number regime, which is very valuable for fragile systems that cannot withstand large photon fluxes. This work proposes an all-optical scheme to deterministically prepare the squeezed Schr$\ddot{\mathrm{o}}$dinger-cat state with high speed and can also be generalized to other physical platforms.