Magnetoelectric phase transition driven by interfacial-engineered Dzyaloshinskii-Moriya interaction

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• Correlated oxides with broken symmetry display diverse phase transitions like superconductivity, magnetism, and ferroelectricity.
• Superlattice construction enables atomic-scale crystal symmetry design for novel emergent orderings and phases.

Purpose of the Study:

• To engineer emergent magnetoelectric phase transitions in superlattices by combining antiferromagnetic Sr₂IrO₄ with ferroelectric SrTiO₃ and BaTiO₃.
• To investigate the role of interfacial Dzyaloshinskii-Moriya interaction in symmetry-engineered quantum phases.

Main Methods:

• Epitaxial fabrication of Sr₂IrO₄/SrTiO₃ and Sr₂IrO₄/BaTiO₃ superlattices.
• Symmetry engineering at the atomic scale to induce emergent phenomena.
• Characterization of magnetoelectric phase transitions and interfacial interactions.

Main Results:

• An emergent magnetoelectric phase transition was achieved in Sr₂IrO₄/SrTiO₃ superlattices.
• An interfacial Dzyaloshinskii-Moriya interaction was identified as the microscopic origin.
• Replacing SrTiO₃ with BaTiO₃ enhanced the transition temperature from 46 K to 203 K and yielded a magnetoelectric coefficient of ~495 mV/cm·Oe.

Conclusions:

• Interfacial engineering of Dzyaloshinskii-Moriya interaction in superlattices is a viable strategy for designing quantum phases.
• This approach offers a pathway to control and enhance emergent orderings in correlated electron systems.