Revelation of topological surface states in Bi 2Se 3 thin films by in situ Al passivation

Murong Lang, Liang He, Faxian Xiu, Xinxin Yu, Jianshi Tang, Yong Wang, Xufeng Kou, Wanjun Jiang, Alexei V. Fedorov, Kang L. Wang

Research output: Contribution to journalArticlepeer-review

82 Citations (Scopus)

Abstract

Figure Persented: Topological insulators (TIs) are extraordinary materials that possess massless, Dirac-like topological surface states in which backscattering is prohibited due to the strong spin-orbit coupling. However, there have been reports on degradation of topological surface states in ambient conditions, which presents a great challenge for probing the original topological surface states after TI materials are prepared. Here, we show that in situ Al passivation inside a molecular beam epitaxy (MBE) chamber could inhibit the degradation process and reveal the pristine topological surface states. Dual evidence from Shubnikov-de Hass (SdH) oscillations and weak antilocalization (WAL) effect, originated from the π Berry phase, suggests that the helically spin-polarized surface states are well preserved by the proposed in situ Al passivation. In contrast, we show the degradation of surface states for the unpassivated control samples, in which the 2D carrier density is increased 39.2% due to ambient n-doping, the SdH oscillations are completely absent, and a large deviation from WAL is observed.

Original languageEnglish
Pages (from-to)295-302
Number of pages8
JournalACS nano
Volume6
Issue number1
DOIs
Publication statusPublished - 2012 Jan 24

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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