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Phase diagram and phonon-induced backscattering in topological insulator nanowires

Dorn, K., De Martino, A. ORCID: 0000-0002-3656-0419 & Egger, R. (2020). Phase diagram and phonon-induced backscattering in topological insulator nanowires. Physical Review B, 101(4-15), 045402. doi: 10.1103/PhysRevB.101.045402


We present an effective low-energy theory of electron-phonon coupling effects for clean cylindrical topological insulator nanowires. Acoustic phonons are modelled by isotropic elastic continuum theory with stress-free boundary conditions. We take into account the deformation potential coupling between phonons and helical surface Dirac fermions, and also include electron-electron interactions within the bosonization approach. For half-integer values of the magnetic flux $\Phi_B$ along the wire, the low-energy theory admits an exact solution since a topological protection mechanism then rules out phonon-induced $2k_F$-backscattering processes. We determine the zero-temperature phase diagram and identify a regime dominated by superconducting pairing of surface states. As example, we consider the phase diagram of HgTe nanowires. We also determine the phonon-induced electrical resistivity, where we find a quadratic dependence on the flux deviation $\delta\Phi_B$ from the nearest half-integer value.

Publication Type: Article
Additional Information: © 2020 American Physical Society
Subjects: Q Science > QC Physics
Departments: School of Science & Technology > Mathematics
Text - Accepted Version
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