Quantum tunneling through planar p–n junctions in HgTe quantum wells

L B Zhang,Kai Chang,H Buhmann,X C Xie,L W Molenkamp

doi:10.1088/1367-2630/12/8/083058

L B Zhang, Kai Chang + Show 3 more

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https://doi.org/10.1088/1367-2630/12/8/083058

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Abstract

We demonstrate that a p–n junction created electrically in HgTe quantum wells with inverted band structure exhibits interesting intraband and interband tunneling processes. We find a perfect intraband transmission for electrons injected perpendicularly to the interface of the p–n junction. The opacity and transparency of electrons through the p–n junction can be tuned by changing the incidence angle, the Fermi energy and the strength of the Rashba spin–orbit interaction (RSOI). The occurrence of a conductance plateau due to the formation of topological edge states in a quasi-one-dimensional (Q1D) p–n junction can be switched on and off by tuning the gate voltage. The spin orientation can be substantially rotated when the samples exhibit a moderately strong RSOI.

Highlights

We demonstrate that a p-n junction created electrically in HgTe quantum wells with inverted band-structure exhibits interesting intraband and interband tunneling processes
Graphene was proposed as a quantum spin Hall (QSH) insulator,[4] but this turned out to be difficult to realize because the spin-orbit interaction (SOI) in this material is too small to create a gap observable in transport experiments
In this Letter we investigate quantum tunneling through planar p-n junctions in HgTe quantum wells (QWs) with inverted band structure

Summary

Introduction

We demonstrate that a p-n junction created electrically in HgTe quantum wells with inverted band-structure exhibits interesting intraband and interband tunneling processes. The opacity and transparency of the tunnel barrier can be controlled by tuning the angle of incidence of the charge carriers, the gate voltage (Fermi energy) and the SOI.

Results

Conclusion