Spin-resolved quantum transport in graphene-based nanojunctions
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- 作者：Jian-Wei Li ; Bin Wang ; Yun-Jin Yu ; Ya-Dong Wei ; Zhi-Zhou Yu…
- 关键词：TMR ; AC conductance ; thermoelectric transport ; NEGF ; DFT
- 刊名：Frontiers of Physics
- 出版年：2017
- 出版时间：August 2017
- 年：2017
- 卷：12
- 期：4
- 全文大小：1,286 KB
- 刊物类别：Physics and Astronomy
- 刊物主题：Physics
Chinese Library of Science - 出版者：Higher Education Press, co-published with Springer-Verlag GmbH
- ISSN：2095-0470
- 卷排序：12
文摘
First-principles calculations were performed to explore the spin-resolved electronic and thermoelectric transport properties of a series of graphene-nanoribbon-based nanojunctions. By flipping the magnetic moments in graphene leads from parallel to antiparallel, very large tunneling magnetoresistance can be obtained under different gate voltages for all the structures. Spin-resolved alternating-current conductance increases versus frequency for the short nanojunctions but decreases for the long nanojunctions. With increasing junction length, the behavior of the junctions changes from capacitive-like to inductive-like. Because of the opposite signs of spin-up thermopower and spin-down thermopower near the Fermi level, pure spin currents can be obtained and large figures of merit can be achieved by adjusting the gate voltage and chemical potential for all the nanojunctions.