Predictable Gate-Field Control of Spin in Altermagnets with Spin-Layer Coupling.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Spintronics utilizes electron spin for data transmission, aiming to overcome conventional electronics limitations.
• Controlling electron spin via electric fields is crucial for practical spintronic applications.

Purpose of the Study:

• To propose and demonstrate a mechanism for generating a static, uniform effective magnetic field using gate-electric fields.
• To explore the potential of two-dimensional altermagnets with spin-layer coupling (SLC) for electric-field-driven spintronics.

Main Methods:

• Utilizing symmetry analysis and ab initio calculations.
• Investigating two-dimensional altermagnets with valley-mediated spin-layer coupling (SLC).
• Predicting altermagnetic monolayer Ca(CoN)2 and related materials as candidates.

Main Results:

• Demonstrated that a uniform gate electric field generates an approximately uniform magnetic field (Bz ∝ Ez) in Ca(CoN)2.
• Achieved high magnetic field strengths (up to ~10^3 T) with moderate electric fields.
• Observed perfect, switchable spin and valley currents, and significant tunneling magnetoresistance.

Conclusions:

• Altermagnetic monolayer Ca(CoN)2 and its family materials are promising for electric-field-controlled spintronics.
• The proposed mechanism offers predictable control of electron spin via electric fields.
• This work opens new avenues for designing advanced spintronic devices operable by purely electric means.