# Effects of different lead magnetizations on the Datta-Das spin field-effect transistor

## TL;DR

This paper investigates how different magnetizations influence the behavior of a Datta-Das spin field-effect transistor with Rashba spin-orbit interactions, revealing conditions for magnetization rotation and current conservation.

## Contribution

It provides a theoretical analysis of spin and charge currents in a Datta-Das transistor considering various reservoir magnetizations and their effects on spin dynamics and current conservation.

## Key findings

- Magnetization components rotate in the plane of the electric field due to SOI.
- Charge current depends on both reservoirs being polarized.
- Transverse spin current is not conserved due to SOI-induced spin injections.

## Abstract

A Datta-Das spin field effect transistor is built of a one-dimensional weak link, with Rashba spin orbit interactions (SOI), which connects two magnetized reservoirs. The particle and spin currents between the two reservoirs are calculated to lowest order in the tunneling through the weak link and in the wide-band approximation, with emphasis on their dependence on the origins of the `bare' magnetizations in the reservoirs. The SOI is found to generate magnetization components in each reservoir, which rotate in the plane of the electric field (generating the SOI) and the weak link, only if the `bare' magnetization of the other reservoir has a non-zero component in that plane. The SOI affects the charge current only if both reservoirs are polarized. The charge current is conserved, but the transverse rotating magnetization current is not conserved since the SOI in the weak link generates extra spin polarizations which are injected into the reservoirs.