In Situ Strain Tuning of the Dirac Surface States in Bi₂Se₃ Films

Journal Article · Thu Aug 02 00:00:00 EDT 2018 · Nano Letters

DOI:https://doi.org/10.1021/acs.nanolett.8b02105· OSTI ID:1581054

Flötotto, David  ^[1]; Bai, Yang ^[1]; Chan, Yang-Hao ^[2]; Chen, Peng ^[3]; Wang, Xiaoxiong ^[4]; Rossi, Paul ^[5]; Xu, Cai-Zhi ^[1]; Zhang, Can ^[1]; Hlevyack, Joseph A. ^[1]; Denlinger, Jonathan D. ^[6]; Hong, Hawoong ^[7]; Chou, Mei-Yin  ^[8]; Mittemeijer, Eric J. ^[9]; Eckstein, James N. ^[1]; Chiang, Tai-Chang ^[10]

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1. Department of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States; Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
2. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
3. Department of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States; Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. College of Science, Nanjing University of Science and Technology, Nanjing 210094, China
5. Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, D-70569 Stuttgart, Germany
6. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
7. Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
8. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan; School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States; Department of Physics, National Taiwan University, Taipei 10617, Taiwan
9. Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, D-70569 Stuttgart, Germany; Institute for Materials Science, University of Stuttgart, Germany
10. Department of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States; Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States; Department of Physics, National Taiwan University, Taipei 10617, Taiwan

Elastic strain has the potential for a controlled manipulation of the band gap and spin-polarized Dirac states of topological materials, which can lead to pseudomagnetic field effects, helical flat bands, and topological phase transitions. However, practical realization of these exotic phenomena is challenging and yet to be achieved. Here we show that the Dirac surface states of the topological insulator Bi₂Se₃ can be reversibly tuned by an externally applied elastic strain. Performing in situ X-ray diffraction and in situ angle-resolved photoemission spectroscopy measurements during tensile testing of epitaxial Bi₂Se₃ films bonded onto a flexible substrate, we demonstrate elastic strains of up to 2.1% and quantify the resulting changes in the topological surface state. Our study establishes the functional relationship between the lattice and electronic structures of Bi₂Se₃ and, more generally, demonstrates a new route toward momentum-resolved mapping of strain-induced band structure changes.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1581054
• Journal Information: Nano Letters, Vol. 18, Issue 9; ISSN 1530-6984
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English