Stability of spin droplets in realistic quantum Hall devices

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 <= nu <= 3. 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 similar to 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 underlines the applicability of spin droplets in, for example, spin-transport through quantum point contacts.