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arXiv · 2401.15553

Unitary and efficient spin squeezing in cavity optomechanics

Lei Xie·Zhiqi Yan·Lingxia Wang·Di Wang·Jinfeng Liu·Yiling Song·Wei Xiong·Mingfeng Wang
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Abstract

We propose an approach to produce spin squeezed states of a large number of nitrogen-vacancy centers in diamond nanostructures coupled to an optical cavity. Unlike the previous squeezing method proposed by Bennett et al. [Phys. Rev. Lett. 110, 156402 (2013)], which is limited by phonon number fluctuations due to the existence of phonon-spin entanglement, our proposal can completely erase the entanglement between spins and hybrid phonon-photon mode mediating the effective spin-spin interaction, and thus achieves unitary one-axis-twisting interactions between nitrogen-vacancy centres, yielding a squeezing scaling $J^{-2/3}$, where J is the total angular momentum. We found that, under certain conditions, our method has the potential to enhance the spin-spin nonlinear interactions. We also proposed a scheme utilizing repeatedly applying the one-axis-twisting evolution to two orthogonal spin directions, which enables the transformation of the one-axis-twisting interactions into two-axis-twisting type, and therefore leads to the spin squeezing with Heisenberg-limited scaling $J^{-1}$. Taking into account the noise effects of spin dephasing and relaxtion, we found that the proposed approaches are robust against imperfections.

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Lei Xie, Zhiqi Yan, Lingxia Wang, Di Wang, Jinfeng Liu, Yiling Song, Wei Xiong, Mingfeng Wang. 2024-01-28. Unitary and efficient spin squeezing in cavity optomechanics. https://arxiv.org/abs/2401.15553

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