Ground-state cooling enabled by critical coupling and dark entangled states

Abstract

We analyze the cooling of a mechanical resonator coupled to an ensemble of interacting two-level systems via an open quantum systems approach. Using an exact analytical result, we find optimal cooling occurs when the phonon mode is critically coupled ($\gamma \sim g$) to the two-level system ensemble. Typical systems operate in sub-optimal cooling regimes due to the intrinsic parameter mismatch ($\gamma \gg g$) between the dissipative decay rate $\gamma$ and the coupling factor $g$. To overcome this obstacle, we show that carefully engineering the coupling parameters through the strain profile of the mechanical resonator allows phonon cooling to proceed through the dark (subradiant) entangled states of an \emph{interacting} ensemble, thereby resulting in optimal phonon cooling. Our results provide a new avenue for ground-state cooling and should be accessible for experimental demonstrations.

11 pages, 4 figures

References in corpus (8)

• Quantum Theory of Cavity-Assisted Sideband Cooling of Mechanical Motion
• Theory of ground state cooling of a mechanical oscillator using dynamical back-action
• Photon-mediated interactions between distant artificial atoms
• Nonreciprocal Photon Transmission and Amplification via Reservoir Engineering
• Dynamic strain-mediated coupling of a single diamond spin to a mechanical resonator
• Observation of Dicke Superradiance for Two Artificial Atoms in a Cavity with High Decay Rate
• Topical Review: Spins and mechanics in diamond
• Cooling a Mechanical Resonator with a Nitrogen-Vacancy Center Ensemble Using a Room Temperature Excited State Spin-Strain Interaction

Cited by in corpus (1)

• Relaxation and pumping of quantum oscillator nonresonantly coupled with the other oscillator