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arXiv · 1612.08869

Local impurity in multichannel Luttinger liquid

V. Kagalovsky·I. V. Lerner·I. V. Yurkevich
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Abstract

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.

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V. Kagalovsky, I. V. Lerner, I. V. Yurkevich. 2016-12-28. Local impurity in multichannel Luttinger liquid. https://doi.org/10.1103/physrevb.95.205122

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