▎ 摘　　要

We theoretically investigate the figure of merit ZT for a quantum wire side-coupled by a graphene sheet and sandwiched between two ferromagnetic electrodes with noncollinear magnetic moments. By using the nonequilibrium Green's function combining with the tight-binding Hamiltonian, we demonstrate that the ZT for the system develops an oscillating behavior and weakly depends on the wire-graphene coupling strength as well as magnetic configuration of the leads. On the contrary, it is strongly dependent on temperature and the polarization strength of the leads. Importantly, the maximum value of ZT for the system without the polarization strength (p=0) is about 1.1 at temperature k(B)T = 0.015 Gamma(0), which is in agreement with the experimental measurements for silicon nanowires.