Effects of scattering area shape on spin conductance in a four-terminal spin-Hall setup

TL;DR

This study investigates how the shape of scattering areas in a four-terminal spin-Hall setup influences spin conductance, revealing shape-dependent variations and stability in ballistic and quasi-ballistic regimes.

Contribution

It introduces the impact of terminal corner roundness on spin conductance patterns in a four-terminal spin-Hall system, highlighting shape effects on energy-dependent conductance.

Findings

Rounder corners lead to oscillatory conductance patterns.

Changing terminal size shifts conductance maxima and minima.

Results are stable in both ballistic and quasi-ballistic regimes.

Abstract

We study spin conductance in a ballistic and quasi-ballistic two dimensional electron system with Rasbha spin-orbit coupling. The system has a four-terminal geometry with round corners at the connection to the leads. It is found that by going from sharp corners to more round corners in the ballistic system the energy depended spin conductance goes from being relatively flat to a curve showing a series of minima and maxima. It is also found that when changing the size of the terminal area by modifying the roundness of the terminal corners the maxima and minima in the transverse spin conductance are shifted in energy. This shift is due increased (decreased) energy for smaller (larger) terminal area. These results were also found to be reasonably stable in quasi-ballistic systems.