Visualizing nanoscale electronic band alignment at the La$_{2/3}$Ca$_{1/3}$MnO$_{3}$/Nb:SrTiO$_{3}$ interface

TL;DR

This study employs cross-sectional scanning tunnelling microscopy and spectroscopy to directly visualize and map the electronic band alignment at the complex oxide interface of La$_{2/3}$Ca$_{1/3}$MnO$_{3}$/Nb:SrTiO$_{3}$, revealing detailed electronic property variations.

Contribution

It introduces a novel approach using XSTM/S to directly measure and visualize electronic band alignment at complex oxide interfaces.

Findings

Direct visualization of band alignment across the heterointerface.

Identification of abrupt changes in mechanical and electronic properties.

Mapping of electronic density of states across the interface.

Abstract

Cross-sectional scanning tunnelling microscopy and spectroscopy (XSTM/S) were used to map out the band alignment across the complex oxide interface of La$_{2/3}$Ca$_{1/3}$MnO$_{3}$/Nb-doped SrTiO$_{3}$. By a controlled cross-sectional fracturing procedure, unit-cell high steps persist near the interface between the thin film and the substrate in the non-cleavable perovskite materials. The abrupt changes of the mechanical and electronic properties were visualized directly by XSTM/S. Using changes in the DOS as probe by STM, the electronic band alignment across the heterointerface was mapped out providing a new approach to directly measure the electronic properties at complex oxide interfaces.