Quantum Collapse of a Skyrmion

We analytically and numerically investigate the quantum collapse of a small skyrmion in a thin magnetic film with Dzyaloshinskii-Moriya interaction (DMI). The stability threshold determined by the DMI, the external magnetic field, and the underlying atomic lattice has been computed. The Lagrangian describing the coupled dynamics of the skyrmion size and the chirality angle has been derived. An instanton solution of the equations of motion that corresponds to the skyrmion underbarrier contraction via quantum tunneling has been obtained. The tunneling rate has been computed and the conditions needed to observe quantum collapse of a skyrmion in a magnetic film have been elucidated [1].

[1] A. Derras-Chouk, E. M. Chudnovsky, and D. A. Garanin, Phys. Rev. B, 98, 024423 (2018)