Berry-phase-mediated topological thermoelectric transport in gapped single and bilayer graphene

Chuanwei Zhang, Sumanta Tewari, S. Das Sarma
2009 Physical Review B  
We consider the anomalous thermoelectric transport in gapped single and bilayer graphene where the gap may be due to broken inversion symmetry. In the presence of the gap, non-trivial Berry phase effects can be shown to mediate a transverse thermoelectric voltage in response to an applied temperature gradient even in the absence of a perpendicular magnetic field. This spontaneous, anomalous Nernst effect is nonzero for non-uniform chemical potential in the two inequivalent valleys in the
more » ... e band structure. Conversely, the Nernst response can be used to create a valley-index polarization between the two transverse sample edges as in the analogous valley Hall effect.
doi:10.1103/physrevb.79.245424 fatcat:5paj5bx2gjh5hdm2tmdiydessi