Thermoelectric figure of merit in a quantum wire coupled to a graphene sheet between ferromagnetic leads Benhu Zhou, Benliang Zhou, Yangsu Zeng, Aihua Zeng and Guanghui Zhou Eur. Phys. J. B, 87 4 (2014) 97 Published online: 23 April 2014 DOI: 10.1140/epjb/e2014-40979-5