Anisotropic spin-dependent thermopower and current in ferromagnetic graphene junctions

• Spin-dependent thermopower in ferromagnetic graphene junctions is studied.
• Spin and charge thermopowers are anisotropic.
• Spin thermopowers can be as large as the charge thermopower.
• A pure spin thermopower (spin current) is obtained.

We study the spin-dependent thermoelectric transport through two-dimensional normal/ferromagnetic/normal/ferromagnetic/normal graphene (NG/FG/NG/FG/NG) junctions. It is found that both charge and spin thermopowers depend on the FGʼs magnetization direction and exhibit an anisotropic behavior. Interestingly, the spin thermopower can be as large as the charge thermopower and even can exceed the latter in magnitude. Moreover, the pure spin thermopower and spin current emerge in this device. The results obtained here suggest a feasible way of enhancing thermospin effects and generating the pure spin current in two-dimensional graphene.