Growing macroscopic superposition states via cavity quantum optomechanics

Abstract

The investigation of macroscopic quantum phenomena is a current active area\nof research that offers significant promise to advance the forefronts of both\nfundamental and applied quantum science. Utilizing the exquisite precision and\ncontrol of quantum optics provides a powerful toolset for generating such\nquantum states where the types and 'size' of the states that can be generated\nare set by the resourcefulness of the protocol applied. In this work we present\na new scheme for 'growing' macroscopic superposition states of motion of a\nmechanical oscillator via cavity quantum optomechanics. The scheme consists of\na series of optical pulses interacting with a mechanical mode via\nradiation-pressure followed by photon-counting measurements. The multistep\nnature of our protocol allows macroscopic superposition states to be prepared\nwith a relaxed requirement for the single-photon optomechanical coupling\nstrength. To demonstrate the feasibility of our scheme, we quantify how initial\nmechanical thermal occupation and decoherence affects the non-classicality and\nmacroscopicity of the states generated. We show that under realistic\nexperimental conditions, mechanical quantum states can exhibit significant\nnon-classicality and can be grown to a macroscopic scale.\n