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arXiv · 2302.03702

Unconditional Wigner-negative mechanical entanglement with linear-and-quadratic optomechanical interactions

Peter McConnell·Oussama Houhou·Matteo Brunelli·Alessandro Ferraro
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Abstract

The generation of entangled states that display negative values of the Wigner function in the quantum phase space is a challenging task, particularly elusive for massive, and possibly macroscopic, systems such as mechanical resonators. In this work, we propose two schemes based on reservoir engineering for generating Wigner-negative entangled states unconditionally. We consider two non-interacting mechanical resonators that are radiation-pressure coupled to either one or two common cavity fields; the optomechanical coupling with the field(s) features both a linear and quadratic part in the mechanical displacement and the cavity is driven at multiple frequencies. We show analytically that both schemes stabilize a Wigner-negative entangled state that combines the entanglement of a two-mode squeezed vacuum with a cubic nonlinearity, which we dub cubic-phase entangled (CPE) state. We then perform extensive numerical simulations to test the robustness of Wigner-negative entanglement attained by approximate CPE states stabilized in the presence of thermal decoherence.

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Peter McConnell, Oussama Houhou, Matteo Brunelli, Alessandro Ferraro. 2023-02-07. Unconditional Wigner-negative mechanical entanglement with linear-and-quadratic optomechanical interactions. https://arxiv.org/abs/2302.03702

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