Fast Generation of High-Fidelity Mechanical Non-Gaussian States via Additional Amplifier and Photon Subtraction

TL;DR

This paper presents a robust protocol for generating high-fidelity non-Gaussian mechanical states, such as Schrödinger cat and Fock states, using an additional amplifier and photon subtraction in optomechanical systems, even with low cooperativity.

Contribution

It introduces a novel method combining amplification and photon subtraction to produce high-quality mechanical NGSs in low-cooperativity regimes, enhancing practical feasibility.

Findings

Protocol achieves near-unit fidelity in state generation.

Effective even when cooperativity is less than one.

Extensible to multi-component cat states.

Abstract

Non-Gaussian states (NGSs) with higher-order correlation properties have wide-range applications in quantum information processing. However, the generation of such states with high quality still faces practical challenges. Here, we propose a protocol to faithfully generate two types of mechanical NGSs, i.e., Schr\"{o}dinger cat states and Fock states, in open optomechanical systems, even when the cooperativity is smaller than one ($g^2/\kappa\gamma<1$). In contrast to the usual scheme, a short squeezed field is pumped to rapidly entangle with a mechanical resonator via a beam-splitter-like optomechanical interaction, effectively reducing the mechanical decoherence. Furthermore, by performing an additional amplifier and a following multi photon subtraction on the entangled optical field, one can selectively obtain the high-fidelity mechanical cat and Fock states. This protocol is robust to various imperfections, allowing it to be implemented with state-of-the-art experimental systems with close to unit fidelity. Moreover, it can be extended to generate a four-component cat state and provide possibilities for future quantum applications of NGSs.