Aharanov-Bohm oscillations and perfectly transmitted mode in amorphous topological insulator nanowires

Fuente: arXiv
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Autores principales: Martínez, Miguel F., Grushin, Adolfo G., Bardarson, Jens H.
Formato: Preprint
Publicado: 2025
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author Martínez, Miguel F.
Grushin, Adolfo G.
Bardarson, Jens H.
author_facet Martínez, Miguel F.
Grushin, Adolfo G.
Bardarson, Jens H.
contents Crystalline topological insulator nanowires with a magnetic flux threaded through their cross section display Aharanov-Bohm conductance oscillations. A characteristic of these oscillations is the perfectly transmitted mode present at certain values of the magnetic flux, due to the appearance of an effective time-reversal symmetry combined with the topological origin of the nanowire surface states. In contrast, amorphous nanowires display a varying cross section along the wire axis that breaks the effective time-reversal symmetry. In this work, we use transport calculations to study the stability of the Aharanov-Bohm oscillations and the perfectly transmitted mode in amorphous topological nanowires. We observe that at low energies and up to moderate amorphicity the transport is dominated, as in the crystalline case, by the presence of a perfectly transmitted mode. In an amorphous nanowire the perfectly transmitted mode is protected by chiral symmetry or, in its absence, by a statistical time-reversal symmetry. At high amorphicities the Aharanov-Bohm oscillations disappear and the conductance is dominated by nonquantized resonant peaks. We identify these resonances as bound states and relate their appearance to a topological phase transition that brings the nanowires into a trivial insulating phase.
format Preprint
id arxiv_https___arxiv_org_abs_2507_02568
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Aharanov-Bohm oscillations and perfectly transmitted mode in amorphous topological insulator nanowires
Martínez, Miguel F.
Grushin, Adolfo G.
Bardarson, Jens H.
Mesoscale and Nanoscale Physics
Disordered Systems and Neural Networks
Crystalline topological insulator nanowires with a magnetic flux threaded through their cross section display Aharanov-Bohm conductance oscillations. A characteristic of these oscillations is the perfectly transmitted mode present at certain values of the magnetic flux, due to the appearance of an effective time-reversal symmetry combined with the topological origin of the nanowire surface states. In contrast, amorphous nanowires display a varying cross section along the wire axis that breaks the effective time-reversal symmetry. In this work, we use transport calculations to study the stability of the Aharanov-Bohm oscillations and the perfectly transmitted mode in amorphous topological nanowires. We observe that at low energies and up to moderate amorphicity the transport is dominated, as in the crystalline case, by the presence of a perfectly transmitted mode. In an amorphous nanowire the perfectly transmitted mode is protected by chiral symmetry or, in its absence, by a statistical time-reversal symmetry. At high amorphicities the Aharanov-Bohm oscillations disappear and the conductance is dominated by nonquantized resonant peaks. We identify these resonances as bound states and relate their appearance to a topological phase transition that brings the nanowires into a trivial insulating phase.
title Aharanov-Bohm oscillations and perfectly transmitted mode in amorphous topological insulator nanowires
topic Mesoscale and Nanoscale Physics
Disordered Systems and Neural Networks
url https://arxiv.org/abs/2507.02568