Light-Induced Mott-Insulator-to-Metal Phase Transition in Ultrathin Intermediate-Spin Ferromagnetic Perovskite...

Area of Science:

• Quantum Materials Science
• Condensed Matter Physics
• Materials Chemistry

Background:

• Perovskite strontium ruthenate (SrRuO3) typically exhibits itinerant ferromagnetism in a low-spin state.
• The intermediate-spin (IS) ferromagnetic metallic phase in SrRuO3 has not been previously observed.
• Controlling quantum phenomena with light is crucial for developing advanced materials.

Purpose of the Study:

• To investigate the possibility of inducing a novel intermediate-spin (IS) ferromagnetic metallic phase in SrRuO3.
• To explore light-induced phase transitions in ultrathin perovskite films.
• To demonstrate optical control over metastable quantum phases.

Main Methods:

• UV-light irradiation of few-atomic-layer perovskite SrRuO3-δ films.
• Utilizing SrTiO3 substrates for photocharge transfer.
• Performing dynamical mean-field theory (DMFT) calculations.

Main Results:

• A Mott-insulator-to-metal phase transition was induced by photocarrier doping using UV light.
• A new, metastable intermediate-spin (IS) ferromagnetic metallic phase was observed in SrRuO3-δ.
• The IS metallic phase was reversibly controlled via photocharge transfer from the substrate.

Conclusions:

• Optical manipulation can induce and control novel metastable phases in strongly correlated systems.
• Photoinduced oxygen vacancies and orbital reconstruction drive the observed electronic phase transformation.
• This research facilitates potential applications in light-controlled optoelectronics and spintronics.