Finite size effects of helical edge states in HgTe/CdTe quantum wells

Abstract

The solutions for the helical edge states for an effective continuum model for the quantum spin Hall effect in HgTe/CdTe quantum wells are presented. For a sample of a large size, the solution gives the linear dispersion for the edge states. However, in a finite strip geometry, the edge states at two sides will couple with each other, which leads to a finite energy gap in the spectra. The gap decays in an exponential law of the width of sample. The magnetic field dependence of the edge states illustrates the difference of the edge states from those of a conventional quantum Hall strip of two-dimensional electron gas.

4 pages, 4 figures

References in corpus (5)

• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• The Helical Liquid and the Edge of Quantum Spin Hall Systems
• Tuning phase transition between quantum spin Hall and ordinary insulating phases
• Two-dimensional spin-filtered chiral network model for the Z_2 quantum spin-Hall effect

Cited by in corpus (3)

• Topological Anderson Insulator
• Coherent Oscillations and Giant Edge Magnetoresistance in Singly Connected Topological Insulators
• Optical manipulation of edge state transport in HgTe quantum wells in the quantum hall regime