Eur. Phys. J. B (2018) 91: 57
https://doi.org/10.1140/epjb/e2018-80552-8

Regular Article

Thermoelectric efficiency enhanced in a quantum dot with polarization leads, spin-flip and external magnetic field

¹ Institute of Theoretical Physics, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan 030006, P.R. China
² Institute of Solid State Physics, Shanxi Datong University, Datong 037009, P.R. China
³ School of Applied Science, Taiyuan University of Science and Technology, Taiyuan 030024, P.R. China

^a e-mail: nieyh@sxu.edu.cn

Received: 30 September 2017
Received in final form: 26 January 2018
Published online: 29 March 2018

Abstract

We theoretically study the thermoelectric transport properties in a quantum dot system with two ferromagnetic leads, the spin-flip scattering and the external magnetic field. The results show that the spin polarization of the leads strongly influences thermoelectric coefficients of the device. For the parallel configuration the peak of figure of merit increases with the increase of polarization strength and non-collinear configuration trends to destroy the improvement of figure of merit induced by lead polarization. While the modulation of the spin-flip scattering on the figure of merit is effective only in the absence of external magnetic field or small magnetic field. In terms of improving the thermoelectric efficiency, the external magnetic field plays a more important role than spin-flip scattering. The thermoelectric efficiency can be significantly enhanced by the magnetic field for a given spin-flip scattering strength.