▎ 摘　　要

We investigate thermally induced spin currents through a two-dimensional normal/ferromagnetic/normal graphene (NG/FG/NG) junction with an energy gap in the FG. By applying temperature difference between two NG electrodes, spin-up and spin-down currents flowing in opposite directions cancel each other out, resulting in pure spin currents. These currents can be modulated by adjusting the gate voltage V-g and the Fermi energy and can flow in the same direction. For nonzero V-g fully polarized currents can be observed. When the NG/FG/NG junction is extended to a NG/FG/NG/FG/NG structure a large thermal magnetoresistance is obtained. These devices can be realized with current technologies and may have practical use in spin caloritronics and quantum information. Copyright (C) EPLA, 2013