Sensing orbital hybridization of graphene-diamond interface with a single spin

TL;DR

This paper introduces a novel method using NV center spin coherence to detect and analyze orbital hybridization of electrons at the graphene-diamond interface with minimal perturbation, revealing new insights into interfacial electronic states.

Contribution

It demonstrates a new experimental approach leveraging weak magnetic interactions and NV centers to probe interfacial electronic properties without disturbing the electrons.

Findings

Significant decrease in electron spin density and coherence time at the interface.

Correlation between interface orbital hybridization and changes in NV spin coherence.

Validation through electron spin resonance spectra and first-principle calculations.

Abstract

Interfacial interactions are crucial in a variety of fields and can greatly affect the electric, magnetic, and chemical properties of materials. Among them, interface orbital hybridization plays a fundamental role in the properties of surface electrons such as dispersion, interaction, and ground states. Conventional measurements of electronic states at interfaces such as scanning tunneling microscopes are all based on electric interactions which, however, suffer from strong perturbation on these electrons. Here we unveil a new experimental detection of interface electrons based on the weak magnetic interactions between them and the nitrogen-vacancy (NV) center in diamond. With negligible perturbation on the interface electrons, their physical properties can be revealed by the NV spin coherence time. In our system, the interface interaction leads to significant decreases in both the density and coherence time of the electron spins at the diamond-graphene interface. Furthermore, together with electron spin resonance spectra and first-principle calculations, we can retrieve the effect of interface electron orbital hybridization. Our study opens a new pathway toward the microscopic probing of interfacial electronic states with weak magnetic interactions and provides a new avenue for future research on material interfaces.