Mean photon number dependent variational method to the Rabi model

Abstract

We present a mean-photon-number dependent variational method, which works well in whole coupling regime if the photon energy is dominant over the spin-flipping, to evaluate the properties of the Rabi model for both the ground state and the excited states. For the ground state, it is shown that the previous approximate methods, the generalized rotating-wave approximation (only working well in the strong coupling limit) and the generalized variational method (only working well in the weak coupling limit), can be recovered in the corresponding coupling limits. The key point of our method is to tailor the merits of these two existing methods by introducing a mean-photon-number dependent variational parameter. For the excited states,our method yields considerable improvements over the generalized rotating-wave approximation. The variational method proposed could be readily applied to the more complex models, for which an analytic formula is difficult to be formulated.

13 pages, 5 figures

References in corpus (20)

• Circuit Quantum Electrodynamics: Coherent Coupling of a Single Photon to a Cooper Pair Box
• Quantum fluids of light
• Beyond the Jaynes-Cummings model: circuit QED in the ultrastrong coupling regime
• On the Integrability of the Rabi Model
• Observation of the Bloch-Siegert Shift in a Qubit-Oscillator System in the Ultrastrong Coupling Regime
• Approaching Unit Visibility for Control of a Superconducting Qubit with Dispersive Readout
• Deep Strong Coupling Regime of the Jaynes-Cummings model
• Climbing the Jaynes-Cummings Ladder and Observing its Sqrt(n) Nonlinearity in a Cavity QED System
• Qubit-oscillator systems in the ultrastrong-coupling regime and their potential for preparing nonclassical states
• Generalized rotating-wave approximation for arbitrarily large coupling
• Dynamics of a two-level system strongly coupled to a high-frequency quantum oscillator
• Ultrafast Quantum Gates in Circuit QED
• Accurate numerical solution to the finite-size Dicke model
• Photonic realization of the quantum Rabi model
• Analytical solutions for the Rabi model
• Qubit-oscillator system: An analytical treatment of the ultra-strong coupling regime
• Absence of Vacuum Induced Berry Phases without the Rotating Wave Approximation in Cavity QED
• Numerical Renormalization Group for the sub-ohmic spin-boson model: A conspiracy of errors
• Quantum phase transition in the delocalized regime of the spin-boson model
• Analytical ground state for the Jaynes-Cummings model with the ultrastrong coupling

Cited by in corpus (15)

• Universal scaling and critical exponents of the anisotropic quantum Rabi model
• Ground-state phase diagram of the quantum Rabi model
• Frequency-renormalized multipolaron expansion for the quantum Rabi model
• Symmetry breaking patterns, tricriticalities and quadruple points in quantum Rabi model with bias and nonlinear interaction
• Hidden Single-Qubit Topological Phase Transition without Gap Closing in Anisotropic Light-Matter Interactions
• Simple variational ground state and pure cat state generation in the quantum Rabi model
• Robust topological feature against non-Hermiticity in Jaynes-Cummings Model
• Nodes and Spin Windings for Topological Transitions in Light-Matter Interactions: \\ Anisotropic Quantum Rabi Model as a Born Abstract Artist
• Characterizing Superradiant Phase of the Quantum Rabi Model
• Universal quantum Fisher information and simultaneous occurrence of Landau-class and topological-class transitions in non-Hermitian Jaynes-Cummings models
• Spin Winding and Topological Nature of Transitions in Jaynes-Cummings Model with Stark Non-linear Coupling
• Quantum Fisher information and polaron picture for identification of transition coupling in quantum Rabi model
• Detection of emitter-resonator coupling strength in quantum Rabi model via an auxiliary resonator
• Low-temperature Quantum Metrology Enhanced by Strong Couplings
• Strong parameter renormalization from optimum lattice model orbitals