Fluctuation-enhanced electron-phonon coupling in FeSe
The study used uniaxial strain to probe how lattice vibrations (phonons) interact with electronic states in FeSe near its nemato-structural transition temperature ($T_s$). They found that strain reveals a subtle asymmetry in a specific phonon mode ($A_{1g}^{ph}$) that appears due to fluctuations right above the transition. This suggests that ordering fluctuations strongly enhance electron-phonon coupling, making the lattice highly sensitive to local symmetry breaking.