# Rare quantum metastable states in the strongly dispersive Jaynes-Cummings oscillator

## TL;DR

This paper investigates rare metastable quantum states in a driven dissipative Jaynes-Cummings oscillator, revealing a long-lived 'dark state' linked to qubit flips and bistability in the strongly dispersive regime.

## Contribution

It provides the first evidence of a long-lived dark state associated with quantum-fluctuation switching in the strongly dispersive Jaynes-Cummings model.

## Key findings

- Identification of a long-lived dark state with quasi-Poissonian statistics
- Correlation between dark state appearance and qubit flips
- Link between dark state and dispersive bistability

## Abstract

We present evidence of metastable rare quantum-fluctuation switching for the driven dissipative Jaynes-Cummings oscillator coupled to a zero-temperature bath in the strongly dispersive regime. We show that single-atom complex amplitude bistability is accompanied by the appearance of a low-amplitude long-lived transient state, hereinafter called `dark state', having a distribution with quasi-Poissonian statistics both for the coupled qubit and cavity mode. We find that the dark state is linked to a spontaneous flipping of the qubit state, detuning the cavity to a low-photon response. The appearance of the dark state is correlated with the participation of the two metastable states in the dispersive bistability, as evidenced by the solution of the Master Equation and single quantum trajectories.