IRG 2: Nonequilibrium Magnetic Phases in Strained Crystalline Membranes

IRG 2 Leaders:

Jason Kawasaki
2152 Engineering Centers Building
1550 Engineering Dr
Madison, WI 53706
(608) 262-3233

Uwe Bergmann
1324 Chamberlin Hall, Thomas C
1150 University Ave
Madison, WI 53706
(608) 262-1152

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