Photon generation and entanglement in a double superconducting cavity

VELASCO, CRUZ I.; DEL GROSSO, NICOLÁS F.; LOMBARDO, FERNANDO C.; SOBA, ALEJANDRO; VILLAR, PAULA I.

Physical Review A

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Año: 2022 vol. 106

2469-9926

We study the dynamical Casimir effect in a double superconducting cavity in a circuit quantum electrodynamicsarchitecture. Parameters in the quantum circuit are chosen in such a way the superconducting cavitycan mimic a double cavity, formed by two perfectly conducting outer walls and a dielectric wall, with arbitrarypermittivity separating both halves. We undertake a spectral analysis of the cavity, showing that the spectrumvaries significantly depending on the values of the susceptibility of the dielectric mirror and the relative lengthsof both cavities. We study the creation of photons when the walls oscillate harmonically with a small amplitude.Furthermore, we explore the possibility of entangling two uncoupled cavities, starting from a symmetric doublecavity and having both of its halves become uncoupled at a later given instant. We consider both cases: (i)when the field is initially in a vacuum state and (ii) the situation in which photon creation via the dynamicalCasimir effect has already taken place. We show that the cavities become entangled in both cases but, in thelatter, the quantum correlation between individual modes can be greatly increased at the cost of diminishing theentanglement between most pairs of modes.