Competing electronic states emerging on polar surfaces

Autor(en)

Michele Reticcioli, Zhichang Wang, Michael Schmid, Dominik Wrana, Lynn A. Boatner, Ulrike Diebold, Martin Setvin, Cesare Franchini

Abstrakt

Excess charge on polar surfaces of ionic compounds is commonly described by the two-dimensional electron gas (2DEG) model, a homogeneous distribution of charge, spatially-confined in a few atomic layers. Here, by combining scanning probe microscopy with density functional theory calculations, we show that excess charge on the polar TaO2 termination of KTaO3(001) forms more complex electronic states with different degrees of spatial and electronic localization: charge density waves (CDW) coexist with strongly-localized electron polarons and bipolarons. These surface electronic reconstructions, originating from the combined action of electron-lattice interaction and electronic correlation, are energetically more favorable than the 2DEG solution. They exhibit distinct spectroscopy signals and impact on the surface properties, as manifested by a local suppression of ferroelectric distortions.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Technische Universität Wien, Xiamen University, Charles University Prague, Oak Ridge National Laboratory , Università di Bologna

Journal

Nature Communications

Band

13

Anzahl der Seiten

7

ISSN

2041-1723

DOI

https://doi.org/10.1038/s41467-022-31953-6

Publikationsdatum

07-2022

Peer-reviewed

Ja

ÖFOS 2012

103009 Festkörperphysik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Chemie, Allgemeine Biochemie, Genetik und Molekularbiologie, General, Allgemeine Physik und Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/cdcc6a0e-6ea2-439d-bcd5-621d721a2884