IRG 2 Leaders:
Jason Kawasaki
2152 Engineering Centers Building
1550 Engineering Dr
Madison, WI 53706
(608) 262-3233
jkawasaki@wisc.edu
Uwe Bergmann
1324 Chamberlin Hall, Thomas C
1150 University Ave
Madison, WI 53706
(608) 262-1152
ubergmann@wisc.edu
More group members
Due to their complex free-energy landscapes with many competing interactions, magnetic materials offer tantalizing opportunities for discovering novel phases of matter, such as skyrmions, merons, and hopfions. Understanding, controlling, and switching between these phases holds promise for applications in high-speed, low-power data processing and storage, next-generation telecommunications, and neuromorphic computing. Existing paradigms for navigating these landscapes, however, have limited ability to steer beyond the nearby phases.
This group combines large, continuously tunable strains and strain gradients, uniquely accessible in single-crystalline membranes, with ultrafast THz, optical, or X-ray excitation to discover hidden magnetic phases that cannot be accessed via small static strains or excitation alone.
The group discovers, understands, and controls nonequilibrium magnetic phases and dynamics via combined extreme strain and ultrafast excitation. Its specific goals are to: (1) Understand how extreme strain and associated symmetry breaking modifies complex free-energy landscapes for magnetism, to place membrane systems near phase boundaries and lower energy barriers. (2) Tune and enhance otherwise weak excitation-induced quasiparticle couplings such as photon-spin and phonon-spin via strain, to enable resonant excitation. And, (3) Combine strong excitation with extreme strain to access nonequilibrium phases and enable ultrafast magnetic switching.
IRG 2 News and Highlights
(2025) Spin-Mechanical Coupling Wisconsin MRSEC in 2D Antiferromagnet CrSBr
Wisconsin MRSEC researchers have demonstrated that strain can dramatically alter the magnetoelastic properties of a two-dimensional material, CrSBr. Magnetoelasticity is the interaction between magnetism and strain. The researchers developed a nanoscale mechanical resonator device to measure the material’s magnetoelastic coupling. Using it, they showed that 2D CrSBr has a particularly large coupling, and that it can be tuned by 50% by stretching the 2D membrane.
October 28, 2025
(2024) Tuning the Magnetic Anisotropy in Artificially Layered Mn3GaN/Mn3Ga Superlattices
Wisconsin MRSEC researchers have create an artificially magnetic material by alternating layers of Mn3GaN and Mn3Ga in perfect atomic registry with one another. The resulting material offers best-of-both worlds performance for advanced electronic devices based on spin. Their magnetism is easy to switch to encode information, but it is stable once set to a specific state. These outstanding properties arise both from the properties of the layers themselves and from the unique atomic environments that exist where the two layers meet. As a result, combining materials this way lets materials scientists design materials that cannot otherwise exist.
October 7, 2025
(2024) Graph Machine Learning for Polycrystals
Polycrystalline materials are everywhere in everyday life, but their microstructure – the arrangement of atoms into crystal grains and grains into a piece of material – covers 10 orders of magnitude in size and involves millions important features. This complexity makes it extremely difficult for scientists to predict the properties of polycrystalline materials quickly and accurately. Wisconsin MRSEC researchers have leveraged the power of machine learning to tame the complexity of polycrystalline materials and predict their properties. They have developed a graph neural network approach that predicts materials properties with >98% accuracy 90,000 times faster than competing methods. They applied this model to predict magnetostriction, which quantifies the size change of a material induced by a magnetic field. Development and design of high magnetostriction materials will enable MRSEC researchers to efficiently control magnetism using mechanical force and enable future technologies such like magnetic soft robots
October 7, 2025
Kawasaki Honored with 2024 MBE Young Investigator Award
The International Conference on Molecular Beam Epitaxy (MBE) has recognized MRSEC IRB 2 Co-Lead, Jason Kawasaki, with the 2024 Young Investigator MBE Award in September. According to the conference’s website, Kawasaki was awarded this honor, “For …
September 30, 2024
Collaborative MRSEC Research Results in Nano Letters Cover Article Last Month
Wisconsin MRSEC research groups (Xiao, Wang, Ping) have made significant progress in understanding and engineering the spin-mechanical coupling properties of two-dimensional materials CrSBr, an air-stable 2D magnet. Using nano-opto-electro-mechanical systems (NOEMS), they have observed the …
September 12, 2024- More IRG 2 posts