Net current generation in a 1D quantum ring at zero magnetic field

TL;DR

This paper investigates how a short THz pulse can induce a net current in a 1D quantum ring at zero magnetic field, exploring effects of asymmetry, impurities, and ratchets through continuous and discrete models.

Contribution

It demonstrates that spatial asymmetry in external excitation can generate a net current in a 1D quantum ring at zero magnetic field, including effects of impurities and ratchets.

Findings

Net current can be generated at zero magnetic field with asymmetric excitation.

Impurities and ratchets influence the magnitude and direction of the induced current.

Both continuous and discrete models show consistent results.

Abstract

We study a non-adiabatic excitation of an electron system in a 1D quantum ring radiated by a short THz pulse. The response of two models, a continuous and discrete, is explored. By introducing a spatial asymmetry in the external perturbation a net current can be generated in the ring at a zero magnetic field. Effect of impurities and ratchets are investigated in combination with symmetric and asymmetric external excitation.