Ratchet effects in Luttinger liquids

TL;DR

This paper explores how electron interactions in a one-dimensional system with two point scatterers lead to a ratchet effect, causing asymmetric conductance and rectification of ac currents, with behavior depending on interaction strength.

Contribution

It demonstrates the emergence of a ratchet effect in Luttinger liquids due to electron interactions and asymmetrical scatterers, revealing new transport phenomena in quantum wires.

Findings

Ratchet current increases with decreasing ac voltage under strong interactions.

Weak interactions cause oscillatory current-voltage behavior.

Asymmetry leads to rectification of ac to dc current.

Abstract

We investigate a one-dimensional electron liquid with two point scatterers of different strength. In the presence of electron interactions, the nonlinear conductance is shown to depend on the current direction. The resulting asymmetry of the transport characteristic gives rise to a ratchet effect, i.e., the rectification of a dc current for an applied ac voltage. In the case of strong repulsive interactions, the ratchet current grows in a wide voltage interval with decreasing ac voltage. In the regime of weak interaction the current-voltage curve exhibits oscillatory behavior. Our results apply to single-band quantum wires and to tunneling between quantum Hall edges.