Thermally driven pure spin current through mesoscopic ferromagnetic semimetal-normal metal junctions

The thermally driven spin transport through mesoscopic ferromagnetic semimetal-normal metal junctions is investigated. A pure spin current can be enforced by the spin-polarised semimetal band structure and the spin current increases with increasing either the temperature bias or the equilibrium temperature in the ballistic transport regime. It is also found that the sign of the spin current can be inverted by a strong spin-flip barrier at the interface of the junction.