Ground state of three qubits coupled to a harmonic oscillator with ultrastrong coupling
Ground state of three qubits coupled to a harmonic oscillator with ultrastrong coupling
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 …