Entangling polaritons via dynamical Casimir effect in circuit quantum electrodynamics

TL;DR

This paper explores how the dynamical Casimir effect can generate and entangle polaritons in circuit QED systems across various coupling regimes, demonstrating robustness against dissipation and proposing protocols for maximally-entangled states.

Contribution

It provides a comprehensive analysis of entanglement generation via the dynamical Casimir effect in different coupling regimes, including protocols for ultrastrong coupling.

Findings

Entanglement can be generated across all coupling regimes.

Robustness of entanglement against dissipative effects.

Feasible protocols for creating maximally-entangled polaritonic states.

Abstract

We investigate how the dynamical Casimir effect can entangle quantum systems in different coupling regimes of circuit quantum electrodynamics, and show the robustness of such entanglement generation against dissipative effects with current technology. We consider two qubit-resonator systems, which are coupled by a SQUID driven with an external magnetic field, and explore the entire range of coupling regimes between each qubit and its respective resonator. In this scheme, we derive a semianalytic explanation for the entanglement generation between both superconducting qubits when they are coupled to their resonators in the strong coupling regime. For the ultrastrong and deep strong coupling regimes, we design feasible protocols to generate maximally-entangled polaritonic states.