Towards spintronics via tunneling through asymmetric barriers

TL;DR

This paper demonstrates theoretically that asymmetric barriers in a one-dimensional fermionic ring can generate directional spin currents, offering a novel approach for spintronics without relying on magnetic fields or spin-orbit coupling.

Contribution

It introduces a simple model showing how asymmetric barriers induce spin-resolved circulating currents in a fermionic ring, a new mechanism for spin transport.

Findings

Directional spin currents arise from barrier asymmetry.

Spin-resolved currents can be controlled by initial state and barrier tuning.

Resonant conditions amplify the spin current effects.

Abstract

Spin transport typically relies on direct manipulation of the spin degree of freedom via magnetic fields, spin-orbit coupling, or engineered spin-dependent potentials. We show theoretically that directional spin currents can arise in a relatively simple setting - a one-dimensional interacting fermionic ring with static, spin-independent asymmetric barriers. By introducing asymmetric potential barrier geometry, spin-resolved circulating currents emerge on a closed chain even for symmetric initial configurations. The effect can be enhanced or reversed by appropriate initial state preparation and tuning the barrier asymmetry to resonant conditions.