Spin-dependent negative differential conductance in transport through single-molecule magnets  

作　　者：罗威 王瑞强 胡梁宾 杨谋 

机构地区：[1]Laboratory of Quantum Information Technology, ICMP and SPTE, South China Normal University

出　　处：《Chinese Physics B》2013年第4期399-405,共7页中国物理B（英文版）

基　　金：Project supported by the Program for New Century Excellent Talents in University of China (Grant No. NCET-10-0090);the National Natural Science Foundation of China (Grant Nos. 10974058, 11174088, and 11274124);the Natural Science Foundation of Guangdong Province of China (Grant No. S2012010010681)

摘　　要：Transport properties are theoretically studied through an anisotropy single-molecule magnet symmetrically connected to two identical ferromagnetic leads. It is found that even though in parallel configuration of leads’ magnetizations, the total current still greatly depends on the spin polarization of leads at certain particular bias region, and thus for large polarization a prominent negative differential conductance （NDC） emerges. This originates from the joint effect of single-direction transitions and spin polarization, which removes the symmetry between spin-up and spin-down transitions. The present mechanism of NDC is remarkably different from the previously reported mechanisms. To clarify the physics of the NDC, we further monitored the shot noise spectroscopy and found that the appearance of the NDC is accompanied by the rapid decrease of Fano factor.Transport properties are theoretically studied through an anisotropy single-molecule magnet symmetrically connected to two identical ferromagnetic leads. It is found that even though in parallel configuration of leads’ magnetizations, the total current still greatly depends on the spin polarization of leads at certain particular bias region, and thus for large polarization a prominent negative differential conductance （NDC） emerges. This originates from the joint effect of single-direction transitions and spin polarization, which removes the symmetry between spin-up and spin-down transitions. The present mechanism of NDC is remarkably different from the previously reported mechanisms. To clarify the physics of the NDC, we further monitored the shot noise spectroscopy and found that the appearance of the NDC is accompanied by the rapid decrease of Fano factor.

关 键 词：SPINTRONICS single-molecule magnets negative differential conductance shot noise 

分 类 号：O561.2[理学—原子与分子物理]