Giant Spin-Valve Effect in Planar Spin Devices Using an Artificially Implemented Nanolength Mott-Insulator Region

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Oxide-based nanoscale planar integrated circuits are crucial for next-generation electronics.
• Oxide materials offer unique properties like ferromagnetism and ferroelectricity, valuable for multifunctional devices.
• Spin-transistor applications require precise conductivity matching, achievable through tunable oxide properties.

Purpose of the Study:

• To demonstrate a large magnetoresistance (MR) ratio in oxide-based spin-valve devices.
• To explore the potential of (La,Sr)MnO3 (LSMO) for advanced spin-transistor applications.
• To develop oxide planar circuits with functionalities surpassing conventional semiconductors.

Main Methods:

• Fabrication of planar-type (La,Sr)MnO3 (LSMO)-based spin-valve devices.
• Implementation of an artificial nanolength Mott-insulator barrier using LSMO phase transition.
• Characterization of magnetoresistance and current modulation in the fabricated devices.

Main Results:

• Achieved a substantially large magnetoresistance (MR) ratio of up to ≈140% in LSMO-based spin-valve devices.
• Demonstrated an MR ratio 10-100 times greater than existing semiconductor-based planar devices.
• Successfully showed current modulation, a key functionality for spin transistors, with a low Mott-insulator barrier height of 55 meV.

Conclusions:

• The developed LSMO-based spin-valve devices offer unprecedented magnetoresistance ratios for spin-transistor applications.
• These findings pave the way for novel oxide planar circuits with unique functionalities not possible with conventional semiconductors.
• The technology holds significant promise for advancing multifunctional electronics.