Large polarons as key quasiparticles in SrTiO3 and SrTiO3-based heterostructures

Abstract

Despite its simple structure and low degree of electronic correlation, SrTiO${}_3$ (STO) features collective phenomena linked to charge transport and, ultimately, superconductivity, that are not yet fully explained. Thus, a better insight in the nature of the quasiparticles shaping the electronic and conduction properties of STO is needed. We studied the low energy excitations of bulk STO and of the LaAlO${}_3$/SrTiO${}_3$ two dimensional electron gas (2DEG) by Ti L${}_3$ edge resonant inelastic x-ray scattering. In all samples, we find the hallmark of polarons in the form of intense $dd$+phonon excitations, and a decrease of the LO3-mode electron-phonon coupling when going from insulating to highly conducting STO single crystals and heterostructures. Both results are attributed to the dynamic screening of the large polaron self-induced polarization, showing that the low temperature physics of STO and STO-based 2DEGs is dominated by large polaron quasiparticles.

arXiv comment5 pages, 4 figures

References in corpus (25)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Resonant Inelastic X-ray Scattering Studies of Elementary Excitations
• Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3
• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3
• Mapping the Spatial Distribution of Charge Carriers in LaAlO3/SrTiO3 Heterostructures
• Theory of spin-orbit coupling at LaAlO3/SrTiO3 interfaces and SrTiO3 surfaces
• Orbital reconstruction and two-dimensional electron gas at the LaAlO3/SrTiO3 interface
• Tailoring the nature and strength of electron-phonon interactions in the SrTiO${}_3$(001) two-dimensional electron liquid
• Electron-phonon interaction and charge carrier mass enhancement in SrTiO3
• Quantum critical origin of the superconducting dome in SrTiO${}_3$
• Common Fermi-liquid origin of T-squared resistivity and superconductivity in n-type SrTiO3
• Efficient implementation of core-excitation Bethe Salpeter equation calculations
• Polaronic metal state at the LaAlO3/SrTiO3 interface
• Polarons from first principles, without supercells
• Many-body large polaron optical conductivity in SrTi${}_{1-x}$Nb${}_x$O${}_3$
• Determining the Electron-Phonon Coupling Strength in Correlated Electron Systems from Resonant Inelastic X-ray Scattering
• Doping-dependent band structure of LaAlO${}_3$/SrTiO${}_3$ interfaces by soft x-ray polarization-controlled resonant angle-resolved photoemission
• Localized vs. delocalized character of charge carriers in LaAlO3/ SrTiO3 superlattices
• Strong energy-momentum dispersion of phonon-dressed carriers in the lightly doped band insulator SrTiO${}_3$
• High Tc superconductivity in superlattices of insulating oxides
• EDRIXS: An open source toolkit for simulating spectra of resonant inelastic x-ray scattering
• Interface superconductivity in LaAlO${}_3$-SrTiO${}_3$ heterostructures
• Generalization of the Franck-Condon model for phonon excitations by resonant inelastic X-ray scattering
• Raman and fluorescence contributions to resonant inelastic soft x-ray scattering on LaAlO${}_3$/SrTiO${}_3$ heterostructures

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• Universal Structural Influence on the 2D Electron Gas at SrTiO${}_3$ Surfaces
• Description of resonant inelastic x-ray scattering in correlated metals
• Probing electron-phonon interactions away from the Fermi level with resonant inelastic x-ray scattering
• Doping-dependence of the electron-phonon coupling in two families of bilayer superconducting cuprates
• Theory of electron-phonon interactions in extended correlated systems probed by resonant inelastic x-ray scattering
• Electronic structure of the frustrated diamond lattice magnet NiRh${}_2$O${}_4$
• Ground state features and spectral properties of large polaron liquids from low to high charge densities
• Two-Dimensional Charge Localization at the Perovskite Oxide Interface
• Evolution of orbital excitations from insulating to superconducting MgTi${}_2$O${}_4$ films
• Orbital inversion and emergent lattice dynamics in infinite layer CaCoO${}_2$
• The influence of phonon symmetry and electronic structure on the electron-phonon coupling momentum dependence in cuprates
• Absence of localized $5d^1$ electrons in KTaO${}_3$ interface superconductors