Transport blocking and topological phases using ac magnetic fields

TL;DR

This paper investigates how ac magnetic fields influence electron dynamics and topological phases in double quantum dots, revealing charge localization and topological transitions controllable by field parameters.

Contribution

It demonstrates the control of charge localization and topological phase transitions in double quantum dots using ac magnetic fields, with conditions derived via Floquet theory.

Findings

Charge localization leads to transport blocking in ESR configuration.

Topological phase transition can be induced by tuning coupling or magnetic field intensity.

Charge localization occurs at quasienergy degeneracies.

Abstract

We analyze electron dynamics and topological properties of open double quantum dots (DQDs) driven by circularly polarized ac-magnetic fields. In particular we focus on the system symmetries which can be tuned by the ac-magnetic field. Remarkably, we show that in the electron spin resonance (ESR) configuration, where the magnetic fields in each dot oscillate with a phase difference of $\pi$, charge localization occurs giving rise to transport blocking at arbitrary intensities of the ac field. The conditions for charge localization are obtained by means of Floquet theory and related with quasienergies degeneracy. We also demonstrate that a topological phase transition can be induced in the adiabatic regime for a phase difference of $\pi$, either by tuning the coupling between dots or by modifying the intensity of the driving magnetic field.