Achieving the Quantum Ground State of a Mechanical Oscillator using a Bose-Einstein Condensate with Back-Action and Cold Damping feedback schemes

TL;DR

This paper demonstrates that a hybrid optomechanical system with a Bose-Einstein condensate can be cooled to its quantum ground state using back-action and cold damping feedback schemes, with efficiency depending on cavity conditions.

Contribution

It introduces and compares two cooling schemes for a BEC-based optomechanical system, highlighting the role of atom interactions and cavity regimes in reaching the ground state.

Findings

Back-action cooling is more effective in the good cavity limit.

Cold damping cooling is more effective in the bad cavity limit.

Presence of BEC enhances cooling efficiency in the cold damping scheme.

Abstract

We present a detailed study to show the possibility of approaching the quantum ground-state of a hybrid optomechanical quantum device formed by a Bose-Einstein condensate (BEC) confined inside a high-finesse optical cavity with an oscillatory end mirror. Cooling is achieved using two experimentally realizable schemes: back-action cooling and cold damping quantum feedback cooling. In both the schemes, we found that increasing the two body atom-atom interaction brings the mechanical oscillator to its quantum ground state. It has been observed that back-action cooling is more effective in the good cavity limit while the cold damping cooling scheme is more relevant in the bad cavity limit. It is also shown that in the cold damping scheme, the device is more efficient in the presence of BEC than in the absence of BEC.