Anomalous Valley Magnetic Moment of Graphene

TL;DR

This paper investigates the effects of four-fermion interactions on the valley magnetic moment in graphene, revealing their relative contributions and drawing parallels to heavy quarkonium systems.

Contribution

It introduces the explicit calculation of four-fermion interaction effects on valley magnetic moments in graphene, highlighting their significance alongside Coulomb interactions.

Findings

Four-fermion interactions contribute about 3% to the valley magnetic moment.

Vertex corrections account for approximately -18% of the magnetic moment.

Carrier interactions in graphene can mimic heavy quarkonium systems.

Abstract

Carrier interactions on graphene are studied. The study shows that besides the well known Coulomb repulsion between carriers, there also exist four-fermion interactions associated with U-process, one of which attracts carriers in different valleys. We then calculate the contributions to valley magnetic moment from vertex correction and from four-fermion corrections explicitly. The relative contributions are -18% and 3% respectively. At last we point out that we can mimic heavy quarkonium system by carrier interactions in graphene.