Flat-lens focusing of electrons on the surface of a topological insulator
Flat-lens focusing of electrons on the surface of a topological insulator
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DOI：
10.1103/physrevb.82.125423
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发表时间：
2010-09-13
影响因子：
3.7
通讯作者：
Beenakker, C. W. J.
中科院分区：
文献类型：
--
作者：
Hassler, F.;Akhmerov, A. R.;Beenakker, C. W. J.
我们提出在三维拓扑绝缘体（如Bi（2）Te（3））的导电表面上实现电子Veselago透镜。这种平面透镜所需的负折射是由于费米面曲率的符号变化，即在足够大的静电势阶跃上从圆形变成雪花状。不需要带间跃迁（如石墨烯）。由于这个原因，并且因为拓扑绝缘体提供了对反向散射的保护，所以电势阶跃能够聚焦宽范围的入射角。我们计算了由点源产生的量子干涉图样，推广了类似的光学计算，包括非圆形费米面（具有非零圆锥常数）的影响
We propose the implementation of an electronic Veselago lens on the conducting surface of a three-dimensional topological insulator (such as Bi(2)Te(3)). The negative refraction needed for such a flat lens results from the sign change in the curvature of the Fermi surface, changing from a circular to a snowflakelike shape across a sufficiently large electrostatic potential step. No interband transition (as in graphene) is needed. For this reason, and because the topological insulator provides protection against backscattering, the potential step is able to focus a broad range of incident angles. We calculate the quantum interference pattern produced by a point source, generalizing the analogous optical calculation to include the effect of a noncircular Fermi surface (having a nonzero conic constant)