Coherent control of levitated nanoparticles via dipole-dipole interaction

We propose a scheme to create and transfer thermal squeezed states and random-phase coherent states in a system of two interacting levitated nanoparticles. In this coupled levitated system, we create a thermal squeezed state of motion in one of the nanoparticles by parametrically driving it and then transferring the state to the other nanoparticle with high fidelity. The transfer mechanism is based on inducing a non-reciprocal type of coupling in the system by suitably modulating the phases of the trapping lasers and the inter-particle distance between the levitated nanoparticles. This non-reciprocal coupling creates a unidirectional channel where information flows from one nanoparticle to the other nanoparticle but not vice versa, thereby allowing for transfer of mechanical states between the nanoparticles with high fidelity. We also affirm this transfer mechanism by creating and efficiently transferring a random-phase coherent state in the coupled levitated system. Further, we make use of the feedback nonlinearity and parametric driving to create simultaneous bistability in the coupled levitated system. Our results may have potential applications in quantum information processing, quantum metrology, and in exploring many-body physics under a controlled environment.