Topological-insulator-based terahertz modulator

Abstract Three dimensional topological insulators, as a new phase of quantum matters, are characterized by an insulating gap in the bulk and a metallic state on the surface. Particularly, most of the topological insulators have narrow band gaps, and hence have promising applications in the area of terahertz optoelectronics. In this work, we experimentally demonstrate an electronically-tunable terahertz intensity modulator based on Bi 1:5 Sb 0:5 Te 1:8 Se 1:2 single crystal, one of the most insulating topological insulators. A relative frequency-independent modulation depth of ~62% over a wide frequency range from 0.3 to 1.4 THz has been achieved at room temperature, by applying a bias current of 100 mA. The…

• UD
  U.S. Department of Energy

  Awards: DE-AC52-06NA25396, AC52-06NA25396
• CF
  Center for Integrated Nanotechnologies

  Award: DE-AC52-06NA25396
• MO
  Ministry of Education, India
• NN
  National Nuclear Security Administration

  Award: DE-AC52-06NA25396
• BE
  Basic Energy Sciences

  Awards: AC52-06NA25396, DE-AC52-06NA25396
• LA
  Los Alamos National Laboratory

  Awards: AC52-06NA25396, DE-AC52-06NA25396