Dissipation Problem Of Quantum Rabi Model With Numerical Simulation

Light and matter interaction has always been one of the important research contents in quantum optics.The quantum Rabi model describes the fundamental interaction between single-mode quantum light field and qubit(two-level quantum system),it is one of the most important physical models in quantum optics and quantum information.The simplified model(Jaynes-Cummings model)under strong coupling conditions has been widely used in quantum state coherent manipulation and quantum information related research.In the present study,the quantum Rabi model is divided into four regimes,weak coupling,strong coupling,ultrastrong coupling and deep strong coupling,depending on the coupling strength between light and matter.In the weak and strong coupling regimes,the JC model with the rotating-wave approximation can accurately solve the system energy levels and eigenstates analytically,it has get great success in quantum computation and quantum information.With the continuous progress of experimental technology and the exploration of theoretical research,the physics problems of ultrastrong coupling and deep strong coupling regimes need to be solved,especially the quantum dissipation problems interacting with the environment.In the ideal cases,quantum systems are usually regarded as isolated systems,without regard to the influence of the environment on the quantum system.But in the real,the interaction between the quantum system and the environment cannot be eliminated,and the process of measurement and information readout are accompanied by the coupling influence of the environment and the quantum system,which will cause quantum dissipation and decoherence.In this paper,we solve the quantum Rabi model with the numerical simulation(Qutip),and obtain its energy eigenvalues and energy eigenstates,using the basis truncation to solve the master equation.In the ultrastrong coupling regime,the time evolution of the excited-state probability of qubit is calculated.The same approach can be used to study the problems of quantum dissipation in quantum Rabi model in deep strong coupling regime.