We report structure, vibrational properties, and weak antilocalization-induced quantum correction to magnetoconductivity in single-crystal ${\mathrm{Bi}}_2\mathrm{Ge}{\mathrm{Te}}_4$. Surface band-structure calculations show a single Dirac cone corresponding to topological surface states in ${\mathrm{Bi}}_2\mathrm{Ge}{\mathrm{Te}}_4$. An estimated phase coherence length, $l_{\varphi }\sim 143\mathrm{nm}$ and prefactor α∼−1.54 from Hikami-Larkin-Nagaoka fitting of magnetoconductivity describe the quantum correction to conductivity. An anomalous temperature dependence of $A_{1g}$ Raman modes confirms enhanced electron-phonon interactions. Our results establish that electrons of the topological state can interact with the phonons involving the vibrations of Bi-Te in ${\mathrm{Bi}}_2\mathrm{Ge}{\mathrm{Te}}_4$.

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• Magnetotransport
• Surface states
• Weak antilocalization
• Single crystal materials
• Topological materials
• Density functional theory
• Raman spectroscopy
• Transmission electron microscopy