Gate control of spin-layer-locking FETs and application to monolayer LuIO

TL;DR

This paper introduces a novel monolayer material, LuIO, with a large Rashba effect suitable for spin-layer locking FETs, and models its gate-controlled spin manipulation for potential spintronic applications.

Contribution

It proposes LuIO as a new 2D material with strong Rashba effects and provides first-principles modeling of its gate-controlled spin-channel switching capabilities.

Findings

LuIO exhibits a Rashba effect up to 0.08 Å$^{-1}$.

Spin rotation of π/2 occurs over just 1 nm.

Doping reduces the energy splitting of spin channels.

Abstract

A recent 2D spinFET concept proposes to switch electrostatically between two separate sublayers with strong and opposite intrinsic Rashba effects. This concept exploits the spin-layer locking mechanism present in centrosymmetric materials with local dipole fields, where a weak electric field can easily manipulate just one of the spin channels. Here, we propose a novel monolayer material within this family, lutetium oxide iodide (LuIO). It displays one of the largest Rashba effects among 2D materials (up to $k_R = 0.08$ {\AA}$^{-1}$), leading to a $\pi/2$ rotation of the spins over just 1 nm. The monolayer had been predicted to be exfoliable from its experimentally-known 3D bulk counterpart, with a binding energy even lower than graphene. We characterize and model with first-principles simulations the interplay of the two gate-controlled parameters for such devices: doping and spin channel selection. We show that the ability to split the spin channels in energy diminishes with doping, leading to specific gate-operation guidelines that can apply to all devices based on spin-layer locking.