Magnetization generation and giant nonlinear transport at symmetry-engineered interfaces

Area of Science:

• Condensed Matter Physics
• Materials Science
• Surface Science

Background:

• Interfaces in heterostructures often retain mirror symmetries, limiting the exploration of diverse physical effects.
• Manipulating these in-plane mirror symmetries on demand presents a significant challenge in materials engineering.

Purpose of the Study:

• To demonstrate a novel strategy for controlling interface in-plane mirror symmetries.
• To engineer LaAlO3/SrTiO3 heterostructures with a specific crystallographic orientation to break pristine symmetries.

Main Methods:

• Designing and fabricating LaAlO3/SrTiO3 heterostructures with a high-index (112) crystallographic orientation.
• Investigating the resulting interface symmetry and electronic properties, including metallic conduction and nonlinear transport phenomena.

Main Results:

• Achieved C_s point symmetry at the (112)-oriented LaAlO3/SrTiO3 interface by breaking pristine mirror symmetries.
• Observed a giant nonlinear Hall effect, circular photogalvanic effect, and current-induced out-of-plane magnetization at room temperature.
• Demonstrated that the nonlinear Hall effect magnitude is comparable to Weyl and Dirac systems.

Conclusions:

• Engineering crystallographic orientation is a viable strategy to control interface symmetry and unlock novel electronic properties.
• The developed LaAlO3/SrTiO3 system with broken symmetries offers a platform for exploring quantum geometry and emergent phenomena.
• This work opens new avenues for designing materials with advanced functionalities based on tailored interface symmetries.