Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 88: Electronic Structure of Surfaces II
O 88.3: Vortrag
Donnerstag, 4. April 2019, 15:30–15:45, H26
In Situ Strain Tuning of the Dirac Surface States in Bi2Se3 Films — •David Flötotto1,2, Yang Bai2, Yang-Hao Chan3, Peng Chen2, Xiaoxiong Wang4, Cai-Zhi Xu2, Joseph A. Hlevyack2, Mei-Yin Chou3, James N. Eckstein2, and Tai-Chang Chiang2 — 1Center for Soft Nanoscience, University of Münster, Germany — 2University of Illinois at Urbana-Champaign, Urbana, USA — 3Academia Sinica, Taipei, Taiwan — 4Nanjing University of Science and Technology, Nanjing, China
A controlled manipulation of the bulk band gap and spin-polarized Dirac surface states of topological insulators is of great fundamental importance and relevant to novel device applications. A promising pathway involves the application of strain, which alters the interatomic lattice spacing thus induces corresponding changes in the electronic band structure. By performing angle-resolved photoemission spectroscopy and X-ray diffraction measurements during in situ tensile tests of ultrathin epitaxial Bi2Se3 films on flexible substrates we demonstrate that the band structure of the prototypical topological insulator Bi2Se3 can be reversibly tuned in situ by applying extrinsic elastic strain of up to 2.1%. In accordance with our first principle calculations, the Dirac point reversibly shifts to larger binding energies with increasing tensile strain as a result of the decreasing inter quintuple-layer distance. Our study is an important step forward towards using strain as an in-situ tool for tailoring of the functional properties of topological materials and opens new routes for a momentum-resolved quantification of strain-induced band-structure changes.