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arXiv · 1410.1965

Generalized rotating-wave approximation to the two-qubit and cavity coupling system

Yu-Yu Zhang·Qing-Hu Chen
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Abstract

The generalized rotating-wave approximation (GRWA) is presented for the two-qubit and cavity coipling system . The analytical expressions in the zeroth order approximation recover the previous adiabatic ones. The counterrotating-wave terms can be eliminated by performing the first order corrections. An effective solvable Hamiltonian with the same form as the ordinary RWA one are then obtained, giving a significantly accurate eigenvalues and eigenstates. Energy levels in the present GRWA are in accordant with the numerical exact diagonalization ones in the a wide range of coupling strength. The atomic population inversion in the GRWA is in quantitative agreement with the numerical results for different detunings in the ultrastrong coupling regime.

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Yu-Yu Zhang, Qing-Hu Chen. 2014-10-08. Generalized rotating-wave approximation to the two-qubit and cavity coupling system. https://doi.org/10.1103/physreva.91.013814

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