Local impurity in a multichannel Luttinger liquid

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Colleges, School and Institutes

External organisations

  • Aston Univ
  • Shamoon College of Engineering, Beer-Sheva 84105, Israel


We investigate the stability of conducting and insulating phases in multichannel Luttinger liquids with respect to embedding a single impurity. We devise a general approach for finding critical exponents of the conductance in the limits of both weak and strong scattering. In contrast to the one-channel Luttinger liquid, the system state in certain parametric regions depends on the scattering strength which results in the emergence of a bistability. Focusing on the two-channel liquid, the method developed here enables us to provide a generic analysis of phase boundaries governed by the most relevant (i.e. not necessarily single-particle) scattering mechanism. The present approach is applicable to channels of different nature as in fermion-boson mixtures, or to identical ones as on the opposite edges of a topological insulator. We show that interaction per se cannot provide protection in particular case of topological insulators realized in narrow Hall bars.


Original languageEnglish
Article number205122
Number of pages10
JournalPhysical Review B
Issue number205122
Publication statusPublished - 15 May 2017