Observation of coherent helimagnons in the Skyrmionic helimagnets

ORAL

Abstract

In MnSi and Fe$_{1-x}$Co$_{x}$Si the interplay between the spin-orbit and exchange interactions leads to a variety of helical magnetically ordered states. Perhaps the most interesting of these is the Skyrmion lattice phase in which the spins form topologically-stabilized vortices which decouple from the host lattice to form their own lattice structure. We use pump-probe reflectivity and Kerr rotation to study the dynamics in these materials, observing coherent collective excitations unique to helimagnets known as helimagnons. Monitoring helimagnon decay in the time-domain directly yields the Gilbert damping parameter in these systems.

*We acknowledge support through DOE contract No. DE-AC02-05CH11231. C.P. and A.B. acknowledge support through DFG TRR80, DFG FOR960, and ERC AdG (291079, TOPFIT).

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Authors

  • Jake Koralek

    • LBNL
    • Lawrence Berkeley National Lab

  • Dennis Meier

    • University of California, Berkeley

  • James Hinton

    • University of California, Berkeley

  • Andreas Bauer

    • Technische Universit\"at M\"unchen

  • Sid Parameswaran

    • University of California, Berkeley

  • Ashvin Vishwanath

    • University of California, Berkeley, and Lawrence Berkeley National Lab

  • Christian Pfleiderer

    • Technische Universit\"at M\"unchen

  • Roomamoorthy Ramesh

    • University of California, Berkeley, and Lawrence Berkeley National Lab

  • Bob Schoenlein

    • Lawrence Berkeley National Lab

  • Joe Orenstein

    • University of California, Berkeley, and Lawrence Berkeley National Lab