Visualization of quasiparticle interference on cubic perovskite oxide surface
Yoshinori Okada1*
1Advanced Institute of Materials Research, Tohoku University, Sendai, Japan
* presenting author:Yoshinori Okada,
Two dimensional (2D) metallic states formed at the surfaces and interfaces of perovskite transition metal oxides have been promising platforms for exploring novel electronic functionalities beyond bulk properties. Although establishing the microscopic guidelines for realizing 2D state is critical factor for further exploration of yet undiscovered phenomena, the atomistic mechanism leading to emergent 2D states remains unknown. Scanning tunneling microscopy/spectroscopy (STM/STS) is an excellent approach to address this problem via simultaneous visualization of atomic arrangements and quasiparticle interference (QPI) patterns: the hallmark for the emergence of coherent 2D electronic states. However, none of the previous studies have succeeded in observing QPI patterns on perovskite oxides. In the presentation, we will show the observation of QPI patterns on an epitaxial thin film surface of cubic perovskite SrVO3(001), together with the observation of apical oxygen superstructures. In combination with first-principles calculations, present atomistic mechanism leading to coherent 2D quasiparticle states on cubic perovskite SrVO3.

Keywords: STM, transition metal perovskite oxides, epitaxial thin film, strongly correlated system