Manipulating electronic structure via vacancies and uniaxial stress.

A fundamental issue in condensed matter physics is the influence of lattice distortion on the electronic structure, which determines physical properties. The lattice is commonly tuned through chemical doping or the application of mechanical stress. Unlike mechanical stress, chemical doping can raise more complications such as impurities, charge count, and local variations. Therefore, it is unclear whether the effects of chemical doping are mainly governed by lattice changes. Here we studied the modification of electronic structure through Te vacancies and uniaxial stress using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT). The results indicate that the appearance or disappearance of primary features in electronic structure due to Te vacancies is reproducible with applied uniaxial stress. Furthermore, DFT calculations imply that these changes in electronic structure are related to the topological phase transition. This suggests various physical properties that show different behavior depending on vacancy concentrations can be manipulated via in-situ uniaxial stress control.