Instituto de Nanociencia y Nanotecnología (INN), CONICET-CNEA. Centro Atómico Bariloche and Instituto Balseiro, San Carlos de Bariloche, Argentina.
«Floquet Entanglement Generation in Parametrically Driven Coupled Superconducting Qubits»
High-fidelity entanglement generation and control are key requirements for
scalable quantum computation, and superconducting circuits provide one of
the leading platforms for their implementation. Beyond their use for fast
gate operations and crosstalk suppression, parametrically driven couplings
also offer a powerful framework for engineering quantum dynamics.
In this talk, I will discuss the dynamical generation of entanglement in
two superconducting qubits coupled through a parametrically driven
longitudinal interaction. Using Floquet theory and exact numerical
simulations, we identify two distinct frequency-matching mechanisms for
entanglement generation: narrow “separable–entangled” (SE) resonances
displaying Landau–Zener–Stückelberg–Majorana interference, and broad
“separable–separable” (SS) resonances leading to robust entanglement
generation. In particular, within a pure SS-resonance regime, the degree of
entanglement can be continuously tuned solely through the driving amplitude.
To describe these effects analytically, we employ generalized Van Vleck
near-degenerate perturbation theory and show that the sustained
entanglement originates from the hybridization of dominant Floquet states.
We also predict the emergence of coherent destruction of entanglement
(CDE), a dynamical suppression mechanism that can occur even in the
presence of a finite avoided crossing in the quasienergy spectrum.