Single-atom laser generates nonlinear coherent states

TL;DR

This paper demonstrates that the stationary state of a single-atom laser is a phase-averaged nonlinear coherent state, revealing unique quantum properties and a new approach to understanding single-atom laser dynamics.

Contribution

It introduces a novel characterization of the single-atom laser's stationary state as a nonlinear coherent state and provides a parametrization method for the deformed annihilation operator.

Findings

Stationary state is a phase-averaged nonlinear coherent state.

Unique solution valid across all laser regimes.

Transition probabilities depend on field intensity.

Abstract

The stationary state of a single-atom (single-qubit) laser is shown to be a phase-averaged nonlinear coherent state - an eigenstate of a specific deformed annihilation operator. The solution found for the stationary state is unique and valid for all regimes of the single-qubit laser operation. We have found the parametrization of the deformed annihilation operator which provides superconvergence in finding the stationary state by iteration. It is also shown that, contrary to the case of the usual laser with constant Einstein coefficients describing transition probabilities, for the single-atom laser the interaction-induced transition probabilities effectively depend on the field intensity.