Details

Autor(en) / Beteiligte

• Glinka, Yuri D
• Babakiray, Sercan
• Johnson, Trent A
• Holcomb, Mikel B
• Lederman, David

Titel

Nonlinear optical observation of coherent acoustic Dirac plasmons in thin-film topological insulators

Ist Teil von

• Nature communications, 2016-09, Vol.7 (1), p.13054-13054, Article 13054

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2016

Link zum Volltext

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• Low-energy collective electronic excitations exhibiting sound-like linear dispersion have been intensively studied both experimentally and theoretically for a long time. However, coherent acoustic plasmon modes appearing in time-domain measurements are rarely observed due to Landau damping by the single-particle continua. Here we report on the observation of coherent acoustic Dirac plasmon (CADP) modes excited in indirectly (electrostatically) opposite-surface coupled films of the topological insulator Bi Se . Using transient second-harmonic generation, a technique capable of independently monitoring the in-plane and out-of-plane electron dynamics in the films, the GHz-range oscillations were observed without corresponding oscillations in the transient reflectivity. These oscillations were assigned to the transverse magnetic and transverse electric guided CADP modes induced by the evanescent guided Lamb acoustic waves and remained Landau undamped due to fermion tunnelling between the opposite-surface Dirac states.