Phonon-Induced Transitions in Time-Reversal Invariant Topological Superconductors

Chen-Hsuan Hsu^1*

¹Institute of Physics, Academia Sinica, Taipei, Taiwan

* Presenter:Chen-Hsuan Hsu, email:chenhsuan@gate.sinica.edu.tw

Time-reversal-invariant topological insulating materials host helical liquids at their boundaries, which facilitate topological superconductivity through local and nonlocal pairings induced by the proximity effect [1,2]. In this work, we explore how phonons influence the topological superconducting phases within proximitized double helical liquids [3]. Through our nonperturbative analysis, we demonstrate that electron-phonon coupling can renormalize pairing operators, thereby enhancing local pair formation. Moreover, phonons are shown to trigger transitions between topological and trivial phases, leading to the suppression of the associated topological zero modes. Considering the omnipresence of phonons, these findings underscore potential challenges in stabilizing topological zero modes within helical channels across various time-reversal-invariant topological insulators.

*This work was financially supported by National Science and Technology Council (NSTC), Taiwan through Grant No. NSTC-112-2112-M-001-025-MY3.

Reference:
[1] Chen-Hsuan Hsu et al., Semicond. Sci. Technol. 36, 123003 (2021), topical review.
[2] Chen-Hsuan Hsu et al., Phys. Rev. Lett. 121, 196801 (2018).
[3] Chen-Hsuan Hsu, Nanoscale Horiz. 9, 1725 (2024).

Keywords: topological insulators, helical liquids, phonons, electron-phonon coupling, topological zero modes