Anomalous optical bistability and robust entanglement of mechanical oscillators using two-photon coherence

TL;DR

This paper demonstrates that two-photon coherence induces optical bistability across all detuning values and enables robust entanglement of mechanical oscillators, even at elevated temperatures, contrasting traditional optomechanical behavior.

Contribution

It reveals that two-photon coherence causes universal optical bistability and strong, temperature-resilient entanglement of mechanical oscillators in optomechanical systems.

Findings

Optical bistability occurs for all cavity-laser detunings due to two-photon coherence.

Unconventional 'ribbon'-shaped hysteresis observed for blue-detuned lasers.

Mirror-mirror entanglement persists up to 12 K environment temperature.

Abstract

Quantum coherence is one of the most intriguing applications of quantum mechanics, and has led to interesting phenomena and uncommon results. Here we show that in a stark contrast to the usual red-detuned condition to observe bistability in single-mode optomechanics, the optical intensities exhibit bistability for all values of cavity-laser detuning due to intermode coupling induced by the two-photon coherence. Interestingly, an unconventional bistability with "ribbon"-shaped hysteresis can be observed for blue-detuned laser frequencies. We also demonstrate that the two-photon coherence leads to a strong entanglement between the movable mirrors in the adiabatic regime. Surprisingly, the mirror-mirror entanglement is shown to persist for environment temperature of the phonon bath up to 12 K using experimental parameters.