Squeezing and entanglement features in parametrically enhanced cavity electro-opto-mechanical converter

•Our research provides another way to prepare squeezed microwave or optical signal via cavity EOM converter enhanced by parametric amplifiers, which provides a firm and efficient preparation platform.•It is common for prior work to utilize extremely low temperature and adiabatic operation method like mechanical dark mode to enhance squeezing and entanglement degree. Indeed, they have achieved enhancements due to the deduction of thermal photons or undesired excitation of phonons. However, these enhancements are limited, as further cooling and perfect adiabatic operation require much more complex technology and delicate craftsmanship. While our proposal probes another option, which enhances squeezing and entanglement feature by effectively strengthening the interaction and coupling between cavity modes and mechanical vibration mode via nonlinear effects of parametrical amplifier. This differs from prior work not only in its form but also its physical realization, which has been theoretically demonstrated to be efficient.•Detailed theoretical analysis and discussions on merits of our proposal are done, which proves the enhancement on microwave-optical entanglement can be achieved by introducing parametric amplifiers. Theoretically, our research will be beneficial for applications of cavity EOM converter and enhancement of these applications. A scheme of parametrically enhanced cavity electro-opto-mechanical converter is proposed in this paper, which utilizes Josephson parametric amplifier and optical parametric amplifier. Basic principles of typical cavity electro-opto-mechanical converter and parametrically enhanced version are introduced briefly. We have probed the squeezing and microwave-optical entanglement performance of the scheme with one or both of the amplifiers. The Wigner distribution of the optical output is obtained to analyze the squeezing effect. Meanwhile, quadrature variances and time domain waveforms of output signals are compared and discussed. The results show that microwave-optical entanglement has been enhanced via nonlinear parametric effects no matter when there is one or two amplifiers. However, single mode squeezing only occurs in the cavity which the amplifier is placed in, and this squeezing effect would not transmit to another cavity which hasn’t been amplified. When both amplifiers are introduced simultaneously, each output of cavity electro-opto-mechanical converter is squeezed independently. Our research provides another way t