Simultaneous Measurement of Resistively and Optically Detected Nuclear Magnetic Resonance in the $\nu=2/3$ Fractional Quantum Hall Regime

TL;DR

This study demonstrates simultaneous resistive and optical detection of nuclear magnetic resonance in the fractional quantum Hall regime at filling factor 2/3, revealing correlated local spin phenomena through resistance and photoluminescence measurements.

Contribution

It introduces a combined measurement approach for NMR detection in the fractional quantum Hall regime, showing that resistance and photoluminescence methods probe similar local nuclear spin dynamics.

Findings

NMR spectra from resistance and PL are qualitatively similar.

Both methods detect Knight shift and zero-shift resonances.

PL intensity changes are linked to nuclear spin polarization effects.

Abstract

We observe nuclear magnetic resonance (NMR) in the fractional quantum Hall regime at Landau level filling factor $\nu=2/3$ from simultaneous measurement of longitudinal resistance and photoluminescence (PL). The dynamic nuclear spin polarization is induced by applying a huge electronic current at the spin phase transition point of $\nu=2/3$. The NMR spectra obtained from changes in resistance and PL intensity are qualitatively the same; that is, the Knight shift (spin polarized region) and zero-shift (spin unpolarized region) resonances are observed in both. The observed change in PL intensity is interpreted as a consequence of the trion scattering induced by polarized nuclear spins. We conclude that both detection methods probe almost the same local phenomena.