Speaker
Description
Topological material $ZrTe_{5}$ exhibits a pronounced resistivity anomaly and a sequence of temperature-dependent electronic reconstructions whose microscopic origin remains under active debate [1,2].
Here, we present a symmetry-resolved Raman scattering study of $ZrTe_{5}$ single crystals in the ac plane over the temperature range 40-300 K. All symmetry-allowed Raman active phonons accessible in the employed polarization configurations were observed, corresponding to six $A_g$ and two $B_2g$ modes. While the phonon energies and linewidths exhibit the expected anharmonic evolution over most of the investigated temperature range, clear deviations from this behaviour emerge near 60 K and 200 K. Several $A_g$ modes and both $B_2g$ modes display pronounced Fano asymmetry, indicating coupling between lattice vibrations and the electronic continuum.
The evolution of phonon energies, linewidths, and Fano parameters reveals two distinct temperature scales that coincide with previously reported transport anomalies. The observed response demonstrates a strong interplay between lattice dynamics and the temperature-dependent electronic structure of $ZrTe_{5}$ and identifies phonon modes that are particularly sensitive to electronic reconstruction in this material.
Acknowledgments
This research is financed by HIP-2D-QM Project. This project received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement NO 101185375
References
[1] Hang Chi et al, “Lifshitz transition mediated electronic transport anomaly in bulk $ZrTe_5$”, New J. Phys. 19 015005 (2017). doi: https://doi.org/10.1103/PhysRevB.106.L081124.
[2] Mohelsky I. et al, "Temperature dependence of the energy band gap in $ZrTe_5$: Implications for the topological phase", Phys. Rev. B 107, L041202 (2023), doi: https://doi.org/10.1103/PhysRevB.107.L041202
