Abstract
We analyze the dissipative conductance of the zero-plateau quantum Hall state appearing in undoped graphene in strong magnetic fields. Charge transport in this state is assumed to be carried by a magnetic domain wall, which forms by hybridization of two counterpropagating edge states of opposing spin due to interactions. The resulting nonchiral edge mode is a Luttinger liquid of parameter , which enters a gapped, perfectly conducting state below a critical value . Backscattering in this system involves spin flip, so that interaction with localized magnetic moments generates a finite resistivity via a “chiral Kondo effect.” At finite temperatures , exhibits a crossover from metallic to insulating behavior as is tuned across a threshold . For , in the intermediate regime is finite, but diverges as approaches . This model provides a natural interpretation of recent experiments.
- Received 17 July 2008
DOI:https://doi.org/10.1103/PhysRevLett.102.206408
©2009 American Physical Society