We consider the phase-transition-like behavior in the Rabi model containing a single two-level system, or qubit, and a single harmonic oscillator. The system experiences a sudden transition from an uncorrelated state to an increasingly correlated one as the qubit-oscillator coupling strength is varied and increased past a critical point. This singular behavior occurs in the limit where the oscillator's frequency is much lower than the qubit's frequency; away from this limit one obtains a finite-width transition region. By analyzing the energy-level structure, the value of the oscillator field and its squeezing and the qubit-oscillator correlation, we gain insight into the nature of the transition and the associated critical behavior.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 23 Jan 2013|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics