# Raman study of electron-phonon coupling in thin films of LiTi$_2$O$_4$ spinel oxide superconductor

## TL;DR

This study uses Raman spectroscopy to investigate electron-phonon interactions in LiTi₂O₄ thin films, revealing specific phonon modes and their coupling behavior, with implications for understanding superconductivity mechanisms.

## Contribution

It provides the first detailed Raman analysis of LiTi₂O₄ thin films, identifying phonon modes and their electron-phonon coupling characteristics, and explores their relation to magnetoresistance transitions.

## Key findings

- Four Raman active modes detected, matching calculations.
- Fano lineshape indicates electron-phonon coupling.
- Coupling anomaly observed at 50 K related to magnetoresistance transition.

## Abstract

We performed a Raman scattering study of thin films of LiTi$_2$O$_4$ spinel oxide superconductor. We detected four out of five Raman active modes, with frequencies in good accordance with our first-principles calculations. Three T$_{2g}$ modes show a Fano lineshape from 5 K to 295 K, which suggests an electron-phonon coupling in LiTi$_2$O$_4$. Interestingly, the electron-phonon coupling shows an anomaly across the negative to positive magnetoresistance transition at 50 K, which may be due to the unset of other competing orders. The strength of the electron-phonon interaction estimated from the Allen's formula and the observed lineshape parameters suggests that the three T$_{2g}$ modes contribute little to superconductivity.