A Spin Field Effect Transistor Based on a Strained Two Dimensional Layer of a Weyl Semimetal

TL;DR

This paper proposes a novel spin field effect transistor based on a strained Weyl semimetal, exhibiting unique oscillatory conductance and sign-switching transconductance, with potential niche applications in spintronics.

Contribution

It introduces a new type of SpinFET using Weyl semimetals with non-classical properties, expanding the scope of spintronic device functionalities.

Findings

Channel conductance oscillates with length at zero gate voltage

Transconductance can switch sign by changing channel length

Potential for CMOS-like complementary device implementation

Abstract

Spin field effect transistors (SpinFET) are an iconic class of spintronic devices that exploit gate tuned spin-orbit interaction in semiconductor channels interposed between ferromagnetic source and drain contacts to elicit transistor functionality. Recently, a new type of SpinFET based on gate tuned strain in quantum materials (e.g. topological insulators) has been proposed and may have interesting analog applications, such as in frequency multiplication, by virtue of its unusual oscillatory transfer characteristic. Here, we propose and analyze yet another type of SpinFET in this class, which may have a different application. It is based on a Weyl semimetal. Because the operating principle is non-classical, the channel conductance shows oscillatory dependence on the channel length at zero gate voltage. Furthermore, the transconductance can switch sign if the channel length is varied. This latter feature can be exploited to implement a complementary device like CMOS by connecting two such SpinFETs of slightly different channel lengths in series. These unusual properties may have niche applications.