The Simulation Of Multi-qubit Quantum Rabi Model And Its Applications On Quantum Information Processing

Quantum Rabi model,which is a fundamental model describing light-matter interaction,plays an important role in various physical systems.In this paper,we propose a theoretical method to simulate multi-qubit quantum Rabi model in a circuit quantum electrodynamics system.By means of external transversal and longitudinal driving fields,an effective Hamiltonian describing the multi-qubit quantum Rabi model is derived.The effective frequency of the resonator and the effective splitting of the qubits depend on the external driving fields.By adjusting the frequencies and the amplitudes of the driving fields,the stronger coupling regimes could be reached.We explore the fidelity of the evolution states as a function of evolution time for multi-qubit under different relative coupling strength by numerical simulation.The numerical simulation shows that our proposal works well in a wide range of parameter space.Next,we illustrate some applications to the simulated multi-qubit QRM on quantum information processing.For example,our scheme can be utilized to generate two-qubit gate,Schr?dinger states,and multi-qubit GHZ states.1.We obtain a quantum gate with maximum quantum entangling power.It is local equivalent to the CNOT gate and it is high fidelity even the system suffering dissipation.2.We can generate the Schr?dinger cat states,and then we study the variation of displacement of the Schr?dinger cat states with parameters and the number of the qubits.3.We also study the Schr?dinger cat states and GHZ states under dissipation.It should be mention that we can obtain high fidelity Schr?dinger cat states and multi-qubit GHZ states even the system suffering dissipation.Finally,we simulate the effective Hamiltonian between a qubit and two resonators in a similar way.By tuning the frequency and amplitude of the external control fields,the stronger coupling regimes could be reached.We show that macroscopic tripartite entangled states and Schr?dinger cat states of two resonators can be generated by this system.