Pure spin current in a double quantum dot device generated by thermal bias

We propose a pure-spin-current thermal generator based on a double quantum dot device. When an external magnetic field is applied on the quantum dots, a pure spin current induced by the thermal bias emerges. This is ascribed to a mirror symmetry configuration of spin-up and spin-down electron transmission probabilities with respect to chemical potentials. Furthermore, the pure spin current can be modulated by the magnetic field and the interdot tunnel coupling. The proposed device can be realized by using today's technologies. (C) 2013 AIP Publishing LLC.