Quantum-Hall to Insulator Transition in Ultra-Low-Carrier-Density Topological Insulator Films and a Hidden Phase of the Zeroth Landau Level

Maryam Salehi, Hassan Shapourian, Ilan Thomas Rosen, Myung Geun Han, Jisoo Moon, Pavel Shibayev, Deepti Jain, David Goldhaber-Gordon, Seongshik Oh

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

A key feature of the topological surface state under a magnetic field is the presence of the zeroth Landau level at the zero energy. Nonetheless, it is challenging to probe the zeroth Landau level due to large electron–hole puddles smearing its energy landscape. Here, by developing ultra-low-carrier density topological insulator Sb2Te3 films, an extreme quantum limit of the topological surface state is reached and a hidden phase at the zeroth Landau level is uncovered. First, an unexpected quantum-Hall-to-insulator-transition near the zeroth Landau level is discovered. Then, through a detailed scaling analysis, it is found that this quantum-Hall-to-insulator-transition belongs to a new universality class, implying that the insulating phase discovered here has a fundamentally different origin from those in nontopological systems.

Original languageEnglish (US)
Article number1901091
JournalAdvanced Materials
Volume31
Issue number36
DOIs
StatePublished - Sep 1 2019

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering

Keywords

  • quantum Hall effect
  • quantum Hall to insulator transition
  • scaling analysis
  • topological insulator thin-films
  • zeroth Landau level

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