Topological nature of step-edge states on the surface of the topological crystalline insulator Pb0.7Sn0.3Se

Davide Iaia, Chang Yan Wang, Yulia Maximenko, Daniel Walkup, R. Sankar, Fangcheng Chou, Yuan Ming Lu, Vidya Madhavan

Research output: Contribution to journalArticlepeer-review

Abstract

In addition to novel surface states, topological insulators can also exhibit robust gapless states at crystalline defects. Step edges constitute a class of common defects on the surface of crystals. In this work we establish the topological nature of one-dimensional (1D) bound states localized at step edges of the (001) surface of a topological crystalline insulator Pb0.7Sn0.3Se, both theoretically and experimentally. We show that the topological stability of the step-edge states arises from an emergent particle-hole symmetry of the surface low-energy physics, and demonstrate the experimental signatures of the particle-hole symmetry breaking. We also reveal the effects of an external magnetic field on the 1D bound states. Our work suggests the possibility of similar topological step-edge modes in other topological materials with a rocksalt structure.

Original languageEnglish (US)
Article number155116
JournalPhysical Review B
Volume99
Issue number15
DOIs
StatePublished - Apr 8 2019

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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