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arXiv 1104.4633cond-mat.mes-hallcond-mat.dis-nncond-mat.str-el
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可调拓扑绝缘体中的拓扑相变和织构反转

Topological Phase Transition and Texture Inversion in a Tunable Topological Insulator

Su-Yang Xu, Y. Xia, L. A. Wray, D. Qian, Shuang Jia, J. H. Dil, F. Meier, J. Osterwalder, B. Slomski, H. Lin, R. J. Cava, M. Z. Hasan

摘要:

最近发现的三维或块状拓扑绝缘体有望表现出奇异的量子现象。一般认为,通过奇数个能带反转调制自旋-轨道相互作用或晶格,可以将平凡绝缘体扭曲成拓扑状态,从而驱动系统通过拓扑量子相变。通过直接测量拓扑不变量(对于直接测量Fu-Kane { $ν_0$ }的方法,参见Hsieh \textit{et.al.,} Science 323,919(2009),http://www.sciencemag.org/content/323/5916/919.abstract),我们报告了在可调谐自旋-轨道系统BiTl(S{1-d}Se{d})2(其是研究最多的拓扑绝缘体Bi 2Se 3的类似物,参见Xia \textit{et.al.,} Nature Phys.5,398(2009),http:http://www.nature.com/nphys/journal/v5/n6/full/nphys1294.html和Spin-Momentum locking,http://www.example.com)中观察到相变。//www.nature.com/nature/journal/v460/n7259/full/nature08234.html),其中首次可视化了拓扑绝缘体状态的形成。在拓扑态下,观察到涡旋状极化态呈现三维矢量织构,当表面自旋动量锁定(Z2拓扑有序)电子通过零载流子密度点时,其拓扑自旋织构发生手性转变.这种相变和织构手征反转可以作为观测\textit{fractional charge}(e/2)等相关分形拓扑现象的物理基础。

英文摘要:

The recently discovered three dimensional or bulk topological insulators are expected to exhibit exotic quantum phenomena. It is believed that a trivial insulator can be twisted into a topological state by modulating the spin-orbit interaction or the crystal lattice via odd number of band inversions, driving the system through a topological quantum phase transition. By directly measuring the topological invariants (for the method to directly measure Fu-Kane {$ν_0$}, see Hsieh \textit{et.al.,} Science 323, 919 (2009) at http://www.sciencemag.org/content/323/5916/919.abstract) we report the observation of a phase transition in a tunable spin-orbit system BiTl(S{1-d}Se{d})2 (which is an analog of the most studied topological insulator Bi2Se3, see Xia \textit{et.al.,} Nature Phys. 5, 398 (2009) at http://www.nature.com/nphys/journal/v5/n6/full/nphys1294.html and Spin-Momentum locking at http://www.nature.com/nature/journal/v460/n7259/full/nature08234.html) where the topological insulator state formation is visualized for the first time. In the topological state, vortex-like polarization states are observed to exhibit 3D vectorial textures, which collectively feature a chirality transition of its topological spin-textures as the spin-momentum locked (Z2 topologically ordered) electrons on the surface go through the zero carrier density point. Such phase transition and texture chirality inversion can be the physical basis for observing \textit{fractional charge} (e/2) and other related fractional topological phenomena.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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