Spin Waves and Magnetic Exchange Hamiltonian in CrSBr

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Magnetism

Background:

• Two-dimensional (2D) van der Waals magnets like chromium sulfur bromide (CrSBr) show technological promise.
• Understanding atomic-scale magnetic interactions is crucial for applications like high-frequency switching.

Purpose of the Study:

• To experimentally determine the magnetic exchange Hamiltonian of CrSBr.
• To characterize the bulk magnon spectrum of CrSBr.

Main Methods:

• Single crystal neutron diffraction to confirm antiferromagnetic order.
• Inelastic neutron scattering to measure magnon dispersions.
• Spin wave model fitting to analyze magnetic exchange interactions.

Main Results:

• Confirmed A-type antiferromagnetic order in CrSBr.
• The magnon spectrum is accurately described by a Heisenberg exchange model with seven nearest in-plane interactions.
• The fitted Hamiltonian predicts chiral magnon edge modes in spin-orbit-enhanced CrSBr heterostructures.

Conclusions:

• The study provides a detailed understanding of CrSBr's magnetic interactions.
• The findings pave the way for designing novel spintronic devices utilizing CrSBr.
• The predicted chiral magnon edge modes offer new avenues for quantum information technologies.