Anomalous thermomagnetic effects in an epitaxial and irradiated graphene monolayer
Abstract
We study valley-dependent anomalous thermomagnetic effects, including the Nernst and Ettingshausen effects, in a graphene monolayer that is subjected to a staggered sublattice potential and off-resonant circularly polarized light. It is found that a topological phase transition in this system can significantly affect the signs of the Nernst conductivity as well as the Ettingshausen thermal conductivity, which provides an alternative method to characterize the phase transition between band and topological insulators. At the topological phase-transition point, pure valley-polarized electric and heat currents are generated. In contrast to traditional thermomagnetism, an anomalous thermomagnetic figure of merit is formulated and used to characterize conversion efficiency. The theoretical approach, including numerical calculations and analytical treatment, can also be used to study the same properties of other graphenelike materials.
- Publication:
-
Physical Review B
- Pub Date:
- December 2015
- DOI:
- 10.1103/PhysRevB.92.235436
- Bibcode:
- 2015PhRvB..92w5436Z
- Keywords:
-
- 73.63.-b;
- 72.15.Jf;
- 73.23.-b;
- Electronic transport in nanoscale materials and structures;
- Thermoelectric and thermomagnetic effects;
- Electronic transport in mesoscopic systems