Atomically Resolved Electronic States and Correlated Magnetic Order at Termination Engineered Complex Oxide...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Surface Science

Background:

• Complex oxide heterostructures, such as bismuth ferrite (BiFeO3) and lanthanum strontium manganite (La0.7Sr0.3MnO3), exhibit emergent properties at interfaces.
• Understanding the electronic structure of these interfaces is crucial for developing novel electronic and spintronic devices.

Purpose of the Study:

• To investigate the electronic states, band gaps, and interface-bound charges at termination-engineered BiFeO3/La0.7Sr0.3MnO3 interfaces.
• To correlate the observed electronic properties with the ferroelectric and magnetic behaviors.
• To elucidate the role of atomic layer stacking sequence in tuning interface properties.

Main Methods:

• Atomically resolved cross-sectional scanning tunneling microscopy (STM) was employed to probe the electronic properties.
• Interface engineering was achieved by controlling the atomic layer stacking sequence during heterostructure fabrication.

Main Results:

• Mapping revealed distinct electronic states and band gaps at the BiFeO3/La0.7Sr0.3MnO3 interface.
• A correlation was established between the atomic stacking sequence and the ferroelectric and magnetic properties.
• The presence of interface-bound charges was identified and linked to specific atomic configurations.

Conclusions:

• The study demonstrates a delicate interplay of correlated physical effects governing the interface properties.
• Engineering the atomic termination and stacking sequence provides a pathway to tune the electronic, ferroelectric, and magnetic characteristics of complex oxide interfaces.
• Direct, atomically resolved access to electronic interface states is essential for understanding and controlling emergent phenomena in complex oxide heterostructures.