Floquet states and persistent currents transitions in a mesoscopic ring

TL;DR

This paper investigates how an oscillating potential influences the energy spectrum and persistent currents in a mesoscopic ring, revealing resonant effects and current sign changes due to Floquet states.

Contribution

It demonstrates the impact of oscillating potentials on persistent currents and introduces the role of Floquet states in mesoscopic quantum rings.

Findings

Oscillating potential significantly affects persistent currents.

Resonant enhancement causes sign reversal of the current.

Floquet states explain the observed phenomena.

Abstract

We consider the effect of an oscillating potential on the single-particle spectrum and the time-averaged persistent current of a one-dimensional phase-coherent mesoscopic ring with a magnetic flux. We show that in a ring with an even number of spinless electrons the oscillating potential has a strong effect on the persistent current when the excited side bands are close to the eigen levels of a pure ring. Resonant enhancement of side bands of the Floquet state generates a sign change of the persistent current.