Magneto-Acoustic Waves in Complex Spin Systems

Introduction

Spintronic devices perform information storage and processing based on the spin degree of freedom. Materials with complex magnetic order, such as ferrimagnets, antiferromagnets, and chiral magnets, are promising candidates for next-generation spintronic devices with ultrafast speed, enhanced robustness, and unique functionalities. However, several fundamental obstacles prevent their efficient control with established approaches based on magnetic fields and electrical currents.

Objectives of MAWiCS

MAWiCS will overcome these obstacles by introducing the magneto-acoustic control of magnetization in these complex spin systems. The advantage of MAWiCS’ approach is based on the following hypotheses:

• Microwave frequency phonons can excite and control antiferromagnetic spin waves and magnetic skyrmion lattices with high efficiency.
• The uniaxial magnetic anisotropy induced by magneto-acoustic interactions can be used for full modulation of antiferromagnetic resonance frequencies.
• Magneto-acoustic waves can propagate in topologically protected skyrmion lattice edge-states with reduced magnetic damping.

Experimental Approaches

MAWiCS will develop innovative experimental approaches to take advantage of symmetry, topology, and exchange-enhancement effects for highly efficient control of spin dynamics in complex spin systems. Consequently, MAWiCS’ results will allow for the first time to:

1. Generate nanoscale spin waves from acoustic pulses in ferrimagnets and antiferromagnets.
2. Control skyrmions by acoustic lattices and realize nanoscale topological acoustics.
3. Excite and detect antiferromagnetic spin waves by acoustic two-tone modulation.

Impact of MAWiCS

MAWiCS’ results will pave the way for the technological realization of magneto-acoustic spintronic devices, enable antiferromagnetic magnonics, and realize topological magnon transport. Ultimately, MAWiCS will thus pioneer a new class of information technology concepts that do not only offer increased performance but also novel functionalities.