Enhanced spin-squeezing using a parametrically-driven cavity

Entangled spin-squeezed states allow the possibility of sensing beyond the standard quantum limit, and have been pursued using a variety of different physical mechanisms. In this talk, we will describe and analyze a new, highly-efficient method for generating spin squeezing that exploits a cavity subject to a two-photon (parametric) drive. Unlike standard methods that use a detuned cavity to induce spin-spin interactions (the “one-axis twist” Hamiltonian), our approach employs a resonant interaction and counterdiabatic driving, leading to a more rapid protocol. Our technique can also achieve true Heisenberg-limited scaling, unlike the standard one-axis twisting approach. We will discuss the main properties of the protocol, and explore its performance in realistic parameter settings. The outlined scheme could be implemented in systems where spin ensembles are coupled to superconducting microwave cavities (e.g. [1]), as well as in systems where spins are strain-coupled to the motion of a nanomechanical resonator (e.g. [2,3]). In both cases, the required resource of a parametric drive is experimentally accessible.

[1] Bienfait, A., et al., Phys Rev X 7.4, 041011 (2017)
[2] Bennett, S. D., et al., Phys Rev Lett 110.15, 156402 (2013)
[3] Lee, D., et al., J. of Opt. 19.3, 033001 (2017)