A New Type of Electron Nuclear-Spin Interaction from Resistively Detected NMR in the Fractional Quantum Hall Effect Regime

TL;DR

This paper reports a novel resistively detected NMR phenomenon in fractional quantum Hall systems, revealing unexpected nuclear-electron spin interactions not explained by existing theories.

Contribution

It introduces a new type of electron-nuclear spin interaction observed via resistively detected NMR in fractional quantum Hall regimes, with unexplained spectral splitting.

Findings

Observation of significant resistance drops at nuclear spin resonance frequencies.

Detection of four sub-line splittings in NMR spectra.

Splitting mechanisms not accounted for by current interaction models.

Abstract

Two dimensional electron gases in narrow GaAs quantum wells show huge longitudinal resistance (HLR) values at certain fractional filling factors. Applying an RF field with frequencies corresponding to the nuclear spin splittings of {69}Ga, {71}Ga and {75}As leads to a substantial decreases of the HLR establishing a novel type of resistively detected NMR. These resonances are split into four sub lines each. Neither the number of sub lines nor the size of the splitting can be explained by established interaction mechanisms.