Engineered Mott ground state in a LaTiO(3+δ)/LaNiO3 heterostructure

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Artificial heterostructures based on LaNiO3 aim to replicate cuprate-like electronic properties.
• Limited experimental understanding exists regarding interfacial charge transfer effects on electronic and orbital states in such systems.

Purpose of the Study:

• To synthesize and investigate the electronic structure of a LaNiO3/LaTiO(3+δ) superlattice.
• To understand interfacial charge transfer and its impact on emergent electronic and orbital properties.

Main Methods:

• Synthesis of a LaNiO3/LaTiO(3+δ) superlattice.
• Resonant X-ray absorption spectroscopy (XAS) and X-ray photoemission spectroscopy (XPS).
• Electrical transport measurements and theoretical calculations.

Main Results:

• Observation of interfacial charge transfer from Ti to Ni sites.
• Emergence of an insulating ground state in the heterostructure.
• Demonstration of orbital polarization and e(g) orbital band splitting at the interface.

Conclusions:

• Interfacial charge transfer is a key mechanism for tuning electronic and orbital properties in artificial heterostructures.
• The LaNiO3/LaTiO(3+δ) system provides a platform for creating exotic electronic, orbital, and spin states.
• Control over interfacial charge is crucial for designing novel quantum materials.