Terahertz plasmonic excitations in Bi2Se3 topological insulator

Plasmons in the terahertz (THz) range have been observed in Bi2Se3 topological insulator films patterned in form of microstructures. These plasmons have been assigned to collective excitations of massless Dirac carriers located onto the Bi2Se3 topological surfaces. Their lifetime is mainly determined by the single-particle scattering rate and results scarcely dependent on temperature as expected for topological carriers.