2015/04/28 by Can-Li Song, Can‐Li Song, Lili Wang +7
Materials Science · Physics and Astronomy · #Condensed matter physics #Dirac fermion #Electron #Graphene #Graphene research and applications #Optics #Physics #Quantum many-body systems #Quantum mechanics #Quasiparticle #Scattering #Spectroscopy #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.114.176602
published as Phys.Rev. Lett. 114, 176602 (2015) · 5 pages, 4 figures, to be published in Physical Review Letters
openalex publication_date 2015/04/28 · arxiv created 2015/05/07 · arxiv updated 2015/05/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Scanning tunneling microscopy and spectroscopy have been used to investigate the femtosecond dynamics of Dirac fermions in the topological insulator Bi2Se3 ultrathin films. At the two-dimensional limit, bulk electrons become quantized and the quantization can be controlled by the film thickness at a single quintuple layer level. By studying the spatial decay of standing waves (quasiparticle interference patterns) off steps, we measure directly the energy and film thickness dependence of the phase relaxation length lϕ and inelastic scattering lifetime τ of topological surface-state electrons. We find that τ exhibits a remarkable (E - EF)(-2) energy dependence and increases with film thickness. We show that the features revealed are typical for electron-electron scattering between surface and bulk states.