Abstract We propose a simple method for generating spin squeezing of atomic ensembles in a Floquet cavity subject to a weak, detuned two-photon driving. We demonstrate that the weak squeezing of light inside the cavity can, counterintuitively, induce strong spin squeezing. This is achieved by exploiting the anti-Stokes scattering process of a photon pair interacting with an atom. Specifically, one photon of the photon pair is scattered into the cavity resonance by absorbing partially the energy of the other photon whose remaining energy excites the atom. The scattering, combined with a Floquet sideband, provides an alternative mechanism to implement Heisenberg-limited spin squeezing. Our proposal does not need multiple classical and cavity-photon drivings applied to atoms in ensembles, and therefore its experimental feasibility is greatly improved compared to other cavity-based schemes. As an example, we demonstrate a possible implementation with a superconducting resonator coupled to a nitrogen-vacancy electronic-spin ensemble.

中文翻译：

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由光在腔内的弱挤压引起的强自旋挤压

摘要 我们提出了一种简单的方法，用于在 Floquet 腔中产生原子集合的自旋压缩，该腔受到弱的、失谐的双光子驱动。我们证明了腔内对光的弱挤压可以与直觉相反地引起强烈的自旋挤压。这是通过利用光子对与原子相互作用的反斯托克斯散射过程来实现的。具体来说，光子对中的一个光子通过部分吸收另一个光子的能量而被散射到谐振腔中，而另一个光子的剩余能量激发了原子。散射与 Floquet 边带相结合，提供了一种实现海森堡限制自旋压缩的替代机制。我们的提议不需要将多个经典和腔光子驱动应用于集合中的原子，因此与其他基于腔的方案相比，其实验可行性大大提高。作为一个例子，我们展示了一个可能的实现，其中超导谐振器与氮空位电子自旋系综耦合。