Spin Hall conductance in a Y-shaped junction device in presence of tunable spin-orbit coupling

TL;DR

This paper investigates how the geometry and tunable spin-orbit interactions in a Y-shaped device influence the spin Hall conductance, revealing symmetry breaking and the effects of different SO terms.

Contribution

It introduces a fabrication technique for Y-shaped devices with adjustable arm angles and analyzes their spin Hall conductance under various spin-orbit interactions.

Findings

Smaller angular separation increases spin Hall conductance.

Breaking of spin rotational symmetry observed.

Different SO interactions produce distinct conductance behaviors.

Abstract

We study spin Hall effect in a three terminal Y-shaped device in presence of tunable spin-orbit (SO) interactions via Landauer-B\"{u}ttiker formalism. We have evolved a fabrication technique for creating different angular separation between the two arms of the Y-shaped device so as to investigate the effect of angular width on the spin Hall conductance (SHC). A smaller angular separation yields a larger conductance. Also arbitrary orientation of the spin quantization axes yields interesting three dimensional contour maps for the SHC corresponding to different angular separation of the Y-shaped device. The results explicitly show breaking of the spin rotational symmetry. Further a systematic study is carried out to compare and contrast between the different SO terms, such as Rashba and Dresselhaus SO interactions and the interplay of the angular separation therein.