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arXiv · 2211.07207

Quantum phase transitions for an integrable quantum Rabi-like model with two interacting qubits

Roberto Grimaudo·Antonio S. M. de Castro·Antonino Messina·Enrique Solano·Davide Valenti
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Abstract

A two-interacting-qubit quantum Rabi-like model with vanishing transverse fields on the qubit-pair is studied. Independently of the coupling regime, this model can be exactly and unitarily reduced to two independent single-spin quantum Rabi models, where the spin-spin coupling plays the role of the transverse field. This transformation and the analytical treatment of the single-spin quantum Rabi model provide the key to prove the integrability of our model. The existence of different first-order quantum phase transitions, characterized by discontinuous two-spin magnetization, mean photon number and concurrence, is brought to light.

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Roberto Grimaudo, Antonio S. M. de Castro, Antonino Messina, Enrique Solano, Davide Valenti. 2022-11-14. Quantum phase transitions for an integrable quantum Rabi-like model with two interacting qubits. https://doi.org/10.1103/physrevlett.130.043602

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