Rabi-type oscillations in a classical Josephson junction

TL;DR

This paper demonstrates that classical Josephson junctions can exhibit Rabi-like oscillations in their phase-locked states, providing insights into classical analogs of quantum phenomena through analytical and numerical analysis.

Contribution

It introduces the concept that classical Josephson junctions can produce Rabi-type oscillations, bridging classical and quantum behaviors in superconducting systems.

Findings

Phase-locked states are modulated in response to perturbations.

Modulation frequency depends on microwave field amplitude.

Classical oscillations resemble quantum Rabi oscillations.

Abstract

We study analytically and numerically the phase-modulation properties of a biased classical Josephson tunnel junction in the zero-voltage state and phase-locked to an external ac field. We show that the phase-locked state is being modulated in the transients, or in response to perturbations, and the modulation frequency is calculated as a function of relevant system parameters, such as microwave field amplitude. The numerical analysis is parameterized similarly to recent experimental results in which a combination of pulsed ac signals and relative switching from the zero-voltage state are used to probe the internal excitations of the junctions. Our analysis demonstrates that the modulation of a phase-locked state in an entirely classical Josephson junction produces oscillations analogous to quantum mechanical Rabi oscillations, expected to be observed under the same conditions.