4 research outputs found
Novel electric field effects on Landau levels in Graphene
A single graphene layer exhibits an anomalous Landau level spectrum. A
massless Dirac like low energy electronic spectrum underlies this anomaly. We
study, analytically and numerically, the effect of a uniform electric field
on the anomalous Landau levels. We solve the problem exactly within the
Dirac cone approximation and find an interesting scaling of the spectrum,
leading to the collapse of the Landau levels at a critical , for a
given magnetic field . We offer a physical interpretation of our result,
which uses `graphene relativity' and the boost operation. Electric fields,
non-uniform at nanoscopic (, magnetic) length scales, produce local
collapse at . We expect an anomalous breakdown of quantum Hall states
in real graphene, induced by large Hall currents.Comment: 4 pages, 3 figure