Amplifying Two-Mode Squeezing in Nanomechanical Resonators

Quantum squeezing plays a crucial role in enhancing the precision of quantum metrology and improving the efficiency of quantum information processing protocols. We thus propose a scheme to amplify two-mode squeezing in nanomechanical resonators, harnessing parametric amplification and two-tone laser controls. The red-detuned laser drives facilitate the cooling of the nanomechanical resonators down to their ground state and allow optimal quantum state transfer in the weak-coupling resolved sideband regime. In particular, the competing blue-detuned lasers in the driving pairs induce displacement squeezing in mechanical resonators. Thus, the quantum state transfer of squeezing in nanomechanical resonators and the intracavity correlated photons of the parametric amplifier significantly enhance two-mode mechanical squeezing. Notably, increasing the coupling strength of the red-detuned laser and the ratio of blue-to-red-detuned laser dramatically amplifies two-mode mechanical squeezing under realistic experimental parameters of a typical optomechanical system. Our findings reveal that the proposed cooperative mechanism effectively enhances the level of two-mode mechanical squeezing with a considerable improvement and demonstrates exceptional resilience to thermal noise.