Observation of Landau level-like quantizations at 77 K along a strained-induced graphene ridge

TL;DR

This study demonstrates Landau level-like quantizations in strained graphene at 77 K, observed via scanning tunnelling spectroscopy, indicating potential for zero-field quantum Hall effects at relatively high temperatures.

Contribution

It provides experimental evidence of strain-induced Landau level-like peaks in graphene at 77 K, advancing understanding of strain effects on electronic properties.

Findings

Nine strain-induced LDOS peaks observed at 77 K

Peak energies follow Landau level progression of Dirac fermions

Potential for zero-field quantum Hall effects at 77 K

Abstract

Recent studies show that the electronic structures of graphene can be modified by strain and it was predicted that strain in graphene can induce peaks in the local density of states (LDOS) mimicking Landau levels (LLs) generated in the presence of a large magnetic field. Here we report scanning tunnelling spectroscopy (STS) observation of nine strain-induced peaks in LDOS at 77 K along a graphene ridge created when the graphene layer was cleaved from a sample of highly oriented pyrolytic graphite (HOPG). The energies of these peaks follow the progression of LLs of massless 'Dirac fermions' (DFs) in a magnetic field of 230 T. The results presented here suggest a possible route to realize zero-field quantum Hall-like effects at 77 K.