Anisotropic thermoelectric effect in helimagnetic tunnel junctions

Thermoelectric transport across normal-metal/helical-multiferroic/ferromagnetic heterojunctions is theoretically investigated. We find an anisotropic charge and spin thermopower with a C(2 nu) symmetry. The angular dependence on the magnetization orientation of the ferromagnetic layer is substantiated by a phenomenological theory based on the symmetry of the effective spin-orbit interaction induced by the topology of the spiral magnetic order in the multiferroic barrier. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3590269]