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arXiv · 1405.0555

Concise analytic solutions to the quantum Rabi model with two arbitrary qubits

Liwei Duan·Shu He·Qing-Hu Chen
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Abstract

Using extended coherent states, an analytical exact study has been carried out for the quantum Rabi model (QRM) with two arbitrary qubits in a very concise way. The $G$-functions with $2 \times 2$ determinants are generally derived. For the same coupling constants, the simplest $G$-function, resembling that in the one-qubit QRM, can be obtained. Zeros of the $G$-function yield the whole regular spectrum. The exceptional eigenvalues, which do not belong to the zeros of the $G$ function, are obtained in the closed form. The Dark states in the case of the same coupling can be detected clearly in a continued-fraction technique. The present concise solution is conceptually clear and practically feasible to the general two-qubit QRM and therefore has many applications.

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Liwei Duan, Shu He, Qing-Hu Chen. 2014-05-03. Concise analytic solutions to the quantum Rabi model with two arbitrary qubits. https://doi.org/10.1016/j.aop.2015.02.003

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