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Transmission through a potential barrier in Luttinger liquids with a topological spin gap

Kainaris, Nikolaos, Carr, Sam T., Mirlin, Alexander D. (2018) Transmission through a potential barrier in Luttinger liquids with a topological spin gap. Physical Review B, 97 (11). Article Number 115107. ISSN 2469-9950. (doi:10.1103/PhysRevB.97.115107) (KAR id:66287)


We study theoretically the transport of the one-dimensional single-channel interacting electron gas through a strong potential barrier in the parameter regime where the spin sector of the low-energy theory is gapped by interaction (Luther-Emery liquid). There are two distinct phases of this nature, of which one is of particular interest as it exhibits nontrivial interaction-induced topological properties. Focusing on this phase and using bosonization and an expansion in the tunneling strength we calculate the conductance through the barrier as a function of the temperature as well as the local density of states (LDOS) at the barrier. Our main result concerns the mechanism of bound-state-mediated tunneling. The characteristic feature of the topological phase is the emergence of protected zero-energy bound states with fractional spin located at the impurity position. By flipping this fractional spin, single electrons can tunnel across the impurity even though the bulk spectrum for spin excitations is gapped. This results in a finite LDOS below the bulk gap and in a nonmonotonic behavior of the conductance. The system represents an important physical example of an interacting symmetry-protected topological phase, which combines features of a topological spin insulator and a topological charge metal, in which the topology can be probed by measuring transport properties.

Item Type: Article
DOI/Identification number: 10.1103/PhysRevB.97.115107
Uncontrolled keywords: Physics of Quantum Materials
Subjects: Q Science > QC Physics > QC173.45 Condensed Matter
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Sam Carr
Date Deposited: 05 Mar 2018 15:19 UTC
Last Modified: 09 Dec 2022 04:09 UTC
Resource URI: (The current URI for this page, for reference purposes)

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