Magnetocrystalline Anisotropy Enables Field-Free Deterministic Switching in Tm₃Fe₅O₁₂/Pt Bilayers: An Atomistic Spin...

Area of Science:

• Spintronics
• Materials Science
• Condensed Matter Physics

Background:

• Scalable and energy-efficient spintronic memory requires deterministic, field-free magnetization switching.
• Existing methods face challenges in achieving reliable control.

Purpose of the Study:

• To uncover the microscopic mechanism of 3-fold rotation and mirror (3m)-symmetric switching in Tm3Fe5O12 (TmIG)/Pt bilayers.
• To establish a symmetry-based design principle for ferrimagnetic spintronic devices.

Main Methods:

• Atomistic spin dynamics simulations were employed.
• Epitaxial (111)-oriented TmIG/Pt bilayers were investigated.
• Comparative simulations were performed on Y3Fe5O12 (YIG).

Main Results:

• Intrinsic cubic magnetocrystalline anisotropy (MCA) of TmIG breaks mirror symmetry, enabling 3m-symmetric torques for field-free switching.
• Switching demonstrates strong angular selectivity and toggle-like behavior under large spin-orbit torque.
• MCA-driven field-free switching is a universal feature in rare-earth iron garnets.

Conclusions:

• Symmetry breaking via MCA is a viable pathway for deterministic, field-free magnetization switching.
• This research provides a design principle for ultrafast, low-power spintronic memory and terahertz spintronics.