Experimental signature of a topological quantum dot

Research output: Contribution to journalArticlepeer-review

Authors

  • Marie S. Rider
  • Maria Sokolikova
  • Peter D Haynes
  • Derek Lee
  • Maddalena Daniele
  • Mariangela Cestelli Guidi
  • Cecilia Mattevi
  • Stefano Lupi
  • Giannini Vincenzo

External organisations

  • Imperial College London
  • University of Rome 'La Sapienza'

Abstract

Topological insulator nanoparticles (TINPs) host topologically protected Dirac surface states, just like their bulk counterparts. For TINPs of radius <100 nm, quantum confinement on the surface results in the discretization of the Dirac cone. This system of discrete energy levels is referred to as a topological quantum dot (TQD) with energy level spacing on the order of Terahertz (THz), which is tunable with material-type and particle size. The presence of these discretized energy levels in turn leads to a new electron-mediated phonon-light coupling in the THz range, and the resulting mode can be observed in the absorption cross-section of the TINPs. We present the first experimental evidence of this new quantum phenomenon in Bi2Te3 topological quantum dots, remarkably observed at room temperature.

Details

Original languageEnglish
Pages (from-to)22817-22825
Number of pages9
JournalNanoscale
Volume12
Issue number44
Early online date4 Nov 2020
Publication statusPublished - 28 Nov 2020

Keywords

  • topology, terahertz, plasmons, topological insulator, quantum theory, quantum dots