Unusual hyperfine interaction of Dirac electrons and NMR spectroscopy in graphene

TL;DR

This paper develops a theoretical framework for NMR in graphene, revealing how the unique Dirac electron dispersion alters hyperfine interactions and identifying regimes with distinct NMR behaviors, suggesting experimental feasibility.

Contribution

It introduces a modified hyperfine interaction model for Dirac electrons in graphene and predicts NMR signatures across different regimes, advancing understanding of spin interactions in 2D materials.

Findings

NMR shift and relaxation times depend on temperature, chemical potential, and magnetic field.

Three regimes identified: Fermi, Dirac-gas, and quantum limit.

NMR detection feasible in enriched graphene samples.

Abstract

Theory of nuclear magnetic resonance (NMR) in graphene is presented. The canonical form of the electron-nucleus hyperfine interaction is strongly modified by the linear electronic dispersion. The NMR shift and spin-lattice relaxation time are calculated as function of temperature, chemical potential, and magnetic field and three distinct regimes are identified: Fermi-, Dirac-gas, and extreme quantum limit behaviors. A critical spectrometer assessment shows that NMR is within reach for fully 13C enriched graphene of reasonable size.