Phonon-mediated electron attraction in SrTiO$_3$ via the generalized Fr\"ohlich and deformation potential mechanisms
Abstract
Superconductivity in doped SrTiO was discovered in 1964, the first superconducting transition observed in a doped semiconductor. However, the mechanism of electron pairing in SrTiO remains a subject of debate. By developing a theoretical framework to incorporate dynamical lattice screening in the electronic Coulomb interactions of semiconductors and insulators, we demonstrate analytically that linear long-range coupling of electrons to multiple longitudinal optical phonons, described by a generalized Fr\"ohlich mechanism, can result in superconductivity in SrTiO. Moreover, by combining our theory with first-principles calculations, we reveal an additional attractive interaction between electrons in SrTiO due to the deformation potential mechanism, arising from the mixed ionic-covalent character of the Ti-O bond. Our results may have implications for the emergence of phonon-mediated electron attraction and superconductivity in a broad range of materials.
Cite
@article{arxiv.2501.17230,
title = {Phonon-mediated electron attraction in SrTiO$_3$ via the generalized Fr\"ohlich and deformation potential mechanisms},
author = {Christopher J. N. Coveney and Norm M. Tubman and Chih-En Hsu and Andres Montoya-Castillo and Marina R. Filip and Jeffrey B. Neaton and Zhenglu Li and Vojtech Vlcek and Antonios M. Alvertis},
journal= {arXiv preprint arXiv:2501.17230},
year = {2025}
}