Preparing a Mechanical Oscillator in Non-Gaussian Quantum States

We propose a protocol for coherently transferring non-Gaussian quantum states from an optical field to a mechanical oscillator. We demonstrate its experimental feasibility in future gravitational-wave detectors and tabletop optomechanical devices. This work not only outlines a feasible way to investigate nonclassicality in macroscopic optomechanical systems, but also presents a new and elegant approach for solving non-Markovian open quantum dynamics in general linear systems.

Figure 1

Possible experimental schemes: (i) an interferometric gravitational-wave detector with kg-scale test masses (left) [13], and (ii) a tabletop coupled cavity scheme with a ng-scale membrane (right) [10].

Figure 2

A model of the optomechanical devices in Fig. 1 (upper left), its spacetime diagram (right), and the couplings (lower left). Ingoing and outgoing rays (tilted lines) are placed on the opposite sides of the oscillator world line (vertical) for clarity. The ingoing field contains a photon pulse, while the outgoing field—containing the information of the oscillator motion—is measured continuously.

Figure 3

Distributions of measurement results (left panels) and the corresponding Wigner function of the oscillator, given the most probable measurement result (middle panels), and less probable result but with a significant non-Gaussianity (right panels).