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arXiv · 1711.10032

Two-photon quantum Rabi model with superconducting circuits

S. Felicetti·D. Z. Rossatto·E. Rico·E. Solano·P. Forn-Díaz
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Abstract

We propose a superconducting circuit to implement a two-photon quantum Rabi model in a solid-state device, where a qubit and a resonator are coupled by a two-photon interaction. We analyze the input-output relations for this circuit in the strong coupling regime and find that fundamental quantum optical phenomena are qualitatively modified. For instance, two-photon interactions are shown to yield single- or two-photon blockade when a pumping field is either applied to the cavity mode or to the qubit, respectively. In addition, we derive an effective Hamiltonian for perturbative ultrastrong two-photon couplings in the dispersive regime, where two- photon interactions introduce a qubit-state-dependent Kerr term. Finally, we analyze the spectral collapse of the multi-qubit two-photon quantum Rabi model and find a scaling of the critical coupling with the number of qubits. Using realistic parameters with the circuit proposed, three qubits are sufficient to reach the collapse point.

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S. Felicetti, D. Z. Rossatto, E. Rico, E. Solano, P. Forn-Díaz. 2017-12-08. Two-photon quantum Rabi model with superconducting circuits. https://doi.org/10.1103/physreva.97.013851

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