Electron-Phonon Coupling and Quantum Correction to Topological Magnetoconductivity in Bi2GeTe4

TL;DR

This study investigates the electron-phonon interactions and quantum corrections in the magnetoconductivity of Bi2GeTe4, revealing topological surface states, significant electron-phonon coupling, and weak-antilocalization effects.

Contribution

It provides the first detailed analysis linking vibrational properties, electron-phonon interactions, and topological surface states in Bi2GeTe4.

Findings

Presence of a single Dirac cone indicating topological surface states

Quantified phase coherence length (~143 nm) and WAL prefactor (~ -1.54)

Enhanced electron-phonon interactions confirmed by Raman mode analysis

Abstract

We report on structure, vibrational properties and weak-antilocalization-(WAL-) induced quantum correction to magnetoconductivity in single crystal Bi2GeTe4. Surface band structure calculations show a single Dirac cone corresponding to topological surface states in Bi2GeTe4. An estimated phase coherence length, l_{\phi} ~ 143 nm and prefactor {\alpha} ~ - 1.54 from Hikami-Larkin-Nagaoka fitting of magnetoconductivity describe the quantum correction to conductivity. An anomalous temperature dependence of A1g Raman modes confirms enhanced electron-phonon interactions. Our results establish the involvement of vibrations of Bi-Te with existence of topological surface states and WAL in Bi2GeTe4.