European Synchrotron Radiation Facility (ESRF), Grenoble (France)
CNR-SPIN Complesso Monte-Santangelo, Napoli (Italy)
CNR-SPIN Complesso Monte-Santangelo, Napoli (Italy); Univ. di Napoli (Italy)
European Synchrotron Radiation Facility (ESRF), Grenoble (France); Max Planck Inst. für Festkörperforschung, Stuttgart (Germany)
Politecnico di Milano (Italy); SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
Politecnico di Milano (Italy); Peking Univ., Beijing (China)
Politecnico di Milano (Italy)
European Synchrotron Radiation Facility (ESRF), Grenoble (France); Politecnico di Milano (Italy)
European Synchrotron Radiation Facility (ESRF), Grenoble (France); Brookhaven National Lab. (BNL), Upton, NY (United States)
Politecnico di Milano (Italy); CNR-SPIN, Milano (Italy)
Despite its simple structure and low degree of electronic correlation, (STO) features collective phenomena linked to charge transport and, ultimately, superconductivity, that are not yet fully explained. Thus, a better insight into 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 two-dimensional electron gas (2DEG) by Ti edge resonant inelastic x-ray scattering. In all samples, we find the hallmark of polarons in the form of intense excitations, and a decrease of the LO3-mode electron-phonon coupling when going from insulating to highly conducting STO single crystals and heterostructures. Overall, 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.
Geondzhian, Andrey, Sambri, Alessia, De Luca, Gabriella M., et al., "Large Polarons as Key Quasiparticles in SrTiO<sub>3</sub> and SrTiO<sub>3</sub>-Based Heterostructures," Physical Review Letters 125, no. 12 (2020), https://doi.org/10.1103/physrevlett.125.126401
@article{osti_1668633,
author = {Geondzhian, Andrey and Sambri, Alessia and De Luca, Gabriella M. and Di Capua, Roberto and Di Gennaro, Emiliano and Betto, Davide and Rossi, Matteo and Peng, Ying Ying and Fumagalli, Roberto and Brookes, Nicholas B. and others},
title = {Large Polarons as Key Quasiparticles in SrTiO<sub>3</sub> and SrTiO<sub>3</sub>-Based Heterostructures},
annote = {Despite its simple structure and low degree of electronic correlation, SrTiO3 (STO) features collective phenomena linked to charge transport and, ultimately, superconductivity, that are not yet fully explained. Thus, a better insight into 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 LaAlO3/SrTiO3 two-dimensional electron gas (2DEG) by Ti L3 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. Overall, 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.},
doi = {10.1103/physrevlett.125.126401},
url = {https://www.osti.gov/biblio/1668633},
journal = {Physical Review Letters},
issn = {ISSN 0031-9007},
number = {12},
volume = {125},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2020},
month = {09}}
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 903https://doi.org/10.1016/j.nima.2018.07.001