Helical fluctuations in the Raman response of the topological insulator Bi2Se3

  title={Helical fluctuations in the Raman response of the topological insulator Bi2Se3},
  author={Vladimir Gnezdilov and Yu. Pashkevich and Helmuth Berger and Ekaterina Pomjakushina and Kazimierz Conder and Peter Lemmens},
  journal={Physical Review B},
The topological insulator Bi2Se3 shows a Raman-scattering (RS) response related to topologically protected surface states amplified by a resonant interband transition. Most significantly this signal has a characteristic Lorentzian lineshape and spin-helical symmetry due to collision-dominated scattering of Dirac states at the Fermi level E-F on bulk-valence states. Its resonance energy, temperature, and doping dependence points to a high selectivity of this process. Its scattering rate (Gamma… 

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