Phonon linewidth due to electron-phonon interactions with strong forward scattering in FeSe thin films on oxide substrates

Abstract

The discovery of an enhanced superconducting transition temperature $T_c$ in monolayers of FeSe grown on several oxide substrates has opened a new route to high-$T_c$ superconductivity through interface engineering. One proposal for the origin of the observed enhancement is an electron-phonon (e-ph) interaction across the interface that peaked at small momentum transfers. In this paper, we examine the implications of such a coupling on the phononic properties of the system. We show that a strong forward scattering leads to a sizable broadening of phonon lineshape, which may result in charge instabilities at long-wavelengths. However, we further find that the inclusion of Coulombic screening significantly reduces the phonon broadening. Our results show that one might not expect anomalously broad phonon linewidths in the FeSe interface systems, despite the fact that the e-ph interaction has a strong peak in the forward scattering (small $q$) direction.

8 pages, 4 figures

References in corpus (6)

• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Universal Substrate Effect on the Superconductivity of FeSe Monolayer Films
• Ubiquitous strong electron phonon coupling at the interface of FeSe/SrTiO3
• Dipolar phonons and electronic screening in monolayer FeSe on SrTiO${}_3$
• The electron-phonon interaction with forward scattering peak is a relevant approach to high Tc superconductivity in FeSe films on SrTiO3 and TiO2
• Charge susceptibility in the t-J model

Cited by in corpus (7)

• Phonon-enhanced superconductivity at the FeSe/SrTiO3 interface
• Dipolar phonons and electronic screening in monolayer FeSe on SrTiO${}_3$
• Novel pairing mechanism for superconductivity at a vanishing level of doping driven by critical ferroelectric modes
• Heterostructural one-unit-cell FeSe/SrTiO3: from high-temperature superconductivity to topological states
• Optical properties and carrier localization in the layered phosphide EuCd${}_2$P${}_2$
• Electronic and phononic properties of a two dimensional electron gas coupled to dipolar phonons via small-momentum-transfer scattering
• Constraints on the total coupling strength to bosons in iron based superconductors