Terahertz Spin-to-Charge Conversion in Strontium Iridate-Based Magnetic Heterostructures.

Area of Science:

• Condensed matter physics
• Materials science
• Spintronics

Background:

• Oxide interfaces are crucial for advanced electronics, enabling phenomena like superconductivity and topological states.
• Previous research primarily focused on gigahertz frequencies, limiting device operational speeds.
• Terahertz (THz) frequency devices offer new possibilities for ultrafast electronics.

Purpose of the Study:

• To investigate ultrafast spin dynamics at oxide interfaces for THz electronics.
• To demonstrate a novel heterostructure for generating an ultrafast inverse spin Hall effect.
• To explore control mechanisms for spin polarization and tailored spin Hall effects.

Main Methods:

• Fabrication of strontium iridate (SrIrO3) heterostructures with cobalt (Co) ultrathin layers.
• Photoexcitation of spins in Co using femtosecond lasers.
• Measurement of spin diffusion and inverse spin Hall effect in sub-picosecond timescales.

Main Results:

• Demonstrated ultrafast spin diffusion from Co to SrIrO3.
• Observed an ultrafast inverse spin Hall effect in sub-picosecond timescales.
• Showcased control over spin polarization and spin Hall effect using magnetic fields and laser fluence.

Conclusions:

• The proposed SrIrO3/Co heterostructure is a viable platform for ultrafast oxide electronics.
• Tailored spin Hall effects can be achieved for THz applications.
• The findings pave the way for room-temperature, next-generation ultrafast electronic devices.