Impurity Effects and Spin Polarizations in a Narrow Quantum Hall System

TL;DR

This study investigates impurity effects and spin polarization behaviors in narrow quantum Hall systems, revealing unique ground states and spin transitions that differ from traditional two-dimensional systems, with implications for optical spectroscopy techniques.

Contribution

It introduces the effects of Gaussian impurities on spin transitions and ground states in narrow quantum Hall systems, highlighting behaviors not observed in standard 2D systems.

Findings

Stable spin partially-polarized state at half-filled quantum Hall state.

Impurities induce novel spin transitions at specific filling factors.

Pair-correlation functions suggest different ground state natures.

Abstract

The temperature dependence of electron spin polarization for a narrow quantum Hall system shows behavior analogous to that of a two-dimensional system at major filling factors. At the lowest half-filled quantum Hall state for which no two-dimensional analog exists, we find a stable spin partially-polarized system. Periodic Gaussian repulsive impurities (antidots) in such a system leads to novel spin transitions at $\nu=\frac13$ and $\nu=\frac12$ and the pair-correlation functions provide clues about nature of different ground states in the system. These results can be explored in optical spectroscopy and optically pumped NMR Knight shift measurements.