Papers
Topics
Authors
Recent
Gemini 2.5 Flash
Gemini 2.5 Flash
173 tokens/sec
GPT-4o
7 tokens/sec
Gemini 2.5 Pro Pro
46 tokens/sec
o3 Pro
4 tokens/sec
GPT-4.1 Pro
38 tokens/sec
DeepSeek R1 via Azure Pro
28 tokens/sec
2000 character limit reached

Helical Edge Modes near Transition to Topological Insulator with Indirect Gap (1011.1711v1)

Published 8 Nov 2010 in cond-mat.mtrl-sci

Abstract: Helical edge modes are characteristic of topological insulators in two dimensions. This paper demonstrates that helical edge modes remain across transitions to ordinary insulators or to semimetals under certain condition. Straight and zigzag edges are considered in a tight-binding model on square lattice. We focus on the case of indirect gap in bulk topological insulators, and obtain the spectrum of edge modes on both sides of transitions. For straight edge, the helical edge mode in topological insulators with strong particle-hole asymmetry has a reentrant region in momentum space. Edge modes show up even in ordinary insulators, but are absent in semimetals. In zigzag edge, the helical edge mode survives in both semimetals and ordinary insulators. However, the edge modes are absent inside the energy gap of ordinary insulators. All results are obtained analytically.

Citations (2)

Summary

We haven't generated a summary for this paper yet.