Ground state of three qubits coupled to a harmonic oscillator with ultrastrong coupling
arXiv:1305.1226 · doi:10.1103/PhysRevA.88.045803
Abstract
We study the Rabi model composed of three qubits coupled to a harmonic oscillator without involving the rotating-wave approximation. We show that the ground state of the three-qubit Rabi model can be analytically treated by using the transformation method, and the transformed ground state agrees well with the exactly numerical simulation under a wide range of qubit-oscillator coupling strengths for different detunings. We use the pairwise entanglement to characterize the ground-state entanglement between any two qubits and show that it has an approximately quadratic dependence on the qubit-oscillator coupling strength. Interestingly, we find that there is no qubit-qubit entanglement for the ground state if the qubit-oscillator coupling strength is large enough.
5 pages, 2 figures, Physical Review A 88, 045803 (2013)
References in corpus (9)
- Observation of the Bloch-Siegert Shift in a Qubit-Oscillator System in the Ultrastrong Coupling Regime
- Deep Strong Coupling Regime of the Jaynes-Cummings model
- Ultra-Strong Light-Matter Coupling Regime with Polariton Dots
- Generalized rotating-wave approximation for arbitrarily large coupling
- Input-output theory of cavities in the ultra-strong coupling regime: the case of a time-independent vacuum Rabi frequency
- Superradiance transition in a system with a single qubit and a single oscillator
- Variational study of a two-level system coupled to a harmonic oscillator in a ultrastrong coupling regime
- Dissipative dynamics of quantum correlations in the strong-coupling regime
- Quantum interference structures in trapped ion dynamics beyond the Lamb-Dicke and rotating wave approximations