Probing Dirac fermion dynamics in topological insulator Bi2Se3 films with a scanning tunneling microscope.
Phys Rev Lett
; 114(17): 176602, 2015 May 01.
Article
em En
| MEDLINE
| ID: mdl-25978246
ABSTRACT
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 lÏ 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.
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01-internacional
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MEDLINE
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En
Ano de publicação:
2015
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Article