Fluctuation-enhanced Kerr nonlinearity in an atom-assisted optomechanical system with atom-cavity interactions

Abstract

We examine the effect of cavity field fluctuations on Kerr nonlinearity in an atom-assisted optomechanical system. It is found that a new self-Kerr (SK) nonlinearity term, which can greatly surpass that of a classical Λ type atomic system when the hybrid system has numerous atoms, is generated based on cavity field fluctuations by atom-cavity interactions. A strong photon–phonon cross-Kerr (CK) nonlinearity is also produced based on cavity field fluctuations. These nonlinearity features can be modified by atom-cavity and optomechanical interactions. This work may provide a new method to enhance the SK nonlinearity and generate the photon–phonon CK nonlinearity.

Entanglement-Based Single-Photon Amplification With High Fidelity of Polarization Feature

“…And there are some methods to make nonlinearities of magnitude 10 -2 , for example with Electromagnetically Induced Transparencies [38], whispering-gallery microresonators [39], and optical fiber systems [40]. Cross-Kerr nonlinearity can be further enhanced in principle with a single two-level atom (with the nonlinear phase shift of π) [41], or atomic gas [42], and atom-assisted optomechanical system [43] as medium with controlled nonlinear coefficients. The nonlinear phase shift required in our proposal can be reduced by increasing the amplitude of the probe beam, because F will be optimal with 2 1.5   in our proposal.…”