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arXiv · 2502.19826

Phonon anomalies within the polar charge density wave phase of the structurally chiral superconductor Mo$_3$Al$_2$C

Shangfei Wu·Xianghan Xu·Fei-Ting Huang·Turan Birol·Sang-Wook Cheong·Girsh Blumberg
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Abstract

We employ polarization-resolved Raman spectroscopy to study the lattice dynamics of the polar charge density wave phase of the superconductor Mo$_3$Al$_2$C with structural chirality. We show the phononic signatures of the charge density wave transition at $T^*$ = 155\,K in Mo$_3$Al$_2$C. The detailed temperature dependence of these phonon modes' frequency, half width at half maximum, and integrated area below $T^*$ reveal anomalies at an intermediate temperature $T' \sim$ 100\,K, especially for the low-energy modes at 130 and 180\,\cm-1. We discuss the origin of these phonon anomalies within the polar charge density wave phase of Mo$_3$Al$_2$C.

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Shangfei Wu, Xianghan Xu, Fei-Ting Huang, Turan Birol, Sang-Wook Cheong, Girsh Blumberg. 2025-02-27. Phonon anomalies within the polar charge density wave phase of the structurally chiral superconductor Mo$_3$Al$_2$C. https://doi.org/10.1103/nkx2-6qyr

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