Stability of spin droplets in realistic quantum Hall devices

TL;DR

This paper investigates the formation and stability of spin droplets in realistic quantum Hall devices, demonstrating their robustness and potential for spin-transport applications through detailed electrostatic and spin-density-functional calculations.

Contribution

It provides the first self-consistent electrostatic and spin-density-functional analysis of spin droplets in realistic quantum Hall device geometries, confirming their stability beyond idealized models.

Findings

Spin droplets form at filling factor ~5/2 in realistic devices.

Spin droplets are stable against geometric deformations.

Features are similar to idealized quantum-dot systems.

Abstract

We study the formation and characteristics of "spin droplets",i.e., compact spin-polarized configurations in the highest occupied Landau level, in an etched quantum Hall device at filling factors $2\leq\nu\leq3$. The confining potential for electrons is obtained with self-consistent electrostatic calculations on a GaAs/AlGaAs heterostructure with experimental system parameters. Real-space spin-density-functional calculations for electrons confined in the obtained potential show the appearance of stable spin droplets at $\nu\sim 5/2$. The qualitative features of the spin droplet are similar to those in idealized (parabolic) quantum-dot systems. The universal stability of the state against geometric deformations underline the applicability of spin droplets in, e.g., spin-transport through quantum point contacts.