【摘要】：正研究了綴飾格子中的量子自旋霍爾效應,模型中同時考慮了Rashba自旋軌道耦合和交換場的作用.綴飾格子具有簡立方對稱性,以零能平帶和單狄拉克錐結構為主要特點.在綴飾格子中,不論是實現(xiàn)量子自旋霍爾效應還是量子反常霍爾效應,都需要一個不為零的內稟自旋軌道耦合作用來打開一個完全的體能隙,這與石墨烯等六角格子模型有著很大的不同.在交換場破壞了時間反演對稱性的情況下,以自旋陳數(shù)為標志的量子自旋霍爾效應仍然能夠存在,邊緣態(tài)和極化率的相關結果也證明了這一結論.結果表明自旋陳數(shù)比z2拓撲數(shù)在表征量子自旋霍爾效應方面有著更廣泛的適用范圍,相應的結論為利用磁場控制量子自旋霍爾效應提出了一個理論模型和依據(jù).
[Abstract]:The quantum spin Hall effect in decorated lattice is studied in this paper. The interaction of Rashba spin orbit coupling and exchange field is considered in the model. The decorated lattice has simple cubic symmetry and is characterized by zero-energy flat band and single Dirac cone structure. In the decorated lattice, whether to realize the quantum spin Hall effect or the quantum anomalous Hall effect, an intrinsic spin orbit coupling action that is not zero is required to open a complete physical gap. This is quite different from the hexagonal lattice model such as graphene. Under the condition that the exchange field destroys the time inversion symmetry, the quantum spin Hall effect marked by spin aging number can still exist, and the results of edge state and polarizability also prove this conclusion. The results show that the spin aging number is more applicable to characterize the quantum spin Hall effect than the z _ 2 topological number. The corresponding results provide a theoretical model and basis for controlling the quantum spin Hall effect by using magnetic field.
【作者單位】： 浙江海洋大學電子信息科學與工程系;浙江海洋大學東�？茖W與技術學院;
【基金】：國家自然科學基金(批準號:11304281,10547001) 浙江省自然科學基金(批準號:LY13D060002)資助的課題~~
【分類號】：O469
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本文編號：2468982