Temperature-controlled giant thermal magnetoresistance behaviors in doped zigzag-edged silicene nanoribbons
Temperature-controlled giant thermal magnetoresistance behaviors in doped zigzag-edged silicene nanoribbons
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DOI：
10.1039/c4ra07791a
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发表时间：
2014-10
期刊：
影响因子：
3.9
通讯作者：
Xifeng Yang;X. Zhang;X. Hong;Y. S. Liu;J. F. Feng;Xiangguo Wang;Chang-wen Zhang
中科院分区：
文献类型：
--
作者：
Xifeng Yang;X. Zhang;X. Hong;Y. S. Liu;J. F. Feng;Xiangguo Wang;Chang-wen Zhang
基于非平衡绿色函数（NEGF）方法和密度泛函理论（DFT）方法，研究了Al-P键对在不同边缘位置掺杂硅烯纳米带（ZSiNRs）的自旋相关热电输运性质.对于铁磁（FM）结构，Al-P键对诱导的局域态与侧量子态之间的强量子相消干涉效应导致费米能级附近出现自旋相关的透射下降。这一事实导致自旋过滤效率和自旋塞贝克系数在费米能级的同时增强，而它们的符号依赖于掺杂位置。此外，对于反铁磁（AFM）结构，Al-P键对可以在费米能级附近引入具有普通洛伦兹形状的自旋相关透射峰。有趣的是，掺杂AFM ZSiNR中的纯自旋电流可以通过调节温度来实现。在这种情况下，自旋过滤器的效率可以达到无穷大，而FM和AFM配置之间的热磁阻（TMR）也可以达到无穷大。
Based on the nonequilibrium Green's function (NEGF) method combined with density functional theory (DFT), we investigate the spin-dependent thermoelectric transport properties of zigzag-edged silicene nanoribbons (ZSiNRs) doped by an Al–P bonded pair at different edge positions. For the ferromagnetic (FM) configuration, the strong quantum destructive interference effects between the localized states induced by the Al–P bonded pair and the side quantum states results in the appearance of spin-dependent transmission dips near the Fermi level. This fact leads to the simultaneous enhancement of the spin-filter efficiency and spin Seebeck coefficient at the Fermi level, while their signs are dependent on the doping positions. Moreover, for the antiferromagnetic (AFM) configuration, the spin-dependent transmission peaks with ordinary Lorentzian shapes near the Fermi level can be introduced by the Al–P bonded pair. Interestingly, a pure spin current in the doped AFM ZSiNRs can be achieved by modulating the temperature. In this case, the spin-filter efficiency can reach infinity, while the thermal magnetoresistance (TMR) between the FM and AFM configurations can also reach infinity.