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arXiv · 2108.08973

Possibility of superradiant phase transitions in coupled two-level atoms

Tao Liu·Yu-Yu Zhang·Qing-Hu Chen·Ke-Lin Wang
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Abstract

Although the oscillator strength sum rule forbids the phase transition in ideal non-interacting two-level atoms systems, we present the possibility of the quantum phase transition in the coupled two-level atoms in a cavity. The system undergoes the superradiant phase transition in the thermodynamics limit and this transition is account for the atom-atom attractive interaction, exhibiting a violation of the sum rule. The bosonic coherent state technique has been adopted to locate the quantum critical point accurately in the finite-size system. We predict the existence of the superadiant phase transition as the number of atoms increases, satisfying all the constraints imposed by the sum rule.

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Tao Liu, Yu-Yu Zhang, Qing-Hu Chen, Ke-Lin Wang. 2021-08-20. Possibility of superradiant phase transitions in coupled two-level atoms. https://doi.org/10.1016/j.physleta.2012.04.053

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