TY - JOUR

T1 - Magnetic skyrmion annihilation by quantum mechanical tunneling

AU - Vlasov, S.M.

AU - Bessarab, P.F.

AU - Lobanov, I.S.

AU - Potkina, M.N.

AU - Uzdin, V.M.

AU - Jónsson, H.

N1 - Publisher Copyright: © 2020 The Author(s). Published by IOP Publishing Ltd on behalf of the Institute of Physics and Deutsche Physikalische Gesellschaft.

PY - 2020/8

Y1 - 2020/8

N2 - Magnetic skyrmions are nano-scale magnetic states that could be used in various spintronics devices. A central issue is the mechanism and rate of various possible annihilation processes and the lifetime of metastable skyrmions. While most studies have focused on classical over-the-barrier mechanism for annihilation, it is also possible that quantum mechanical tunneling through the energy barrier takes place. Calculations of the lifetime of magnetic skyrmions in a two-dimensional lattice are presented and the rate of tunneling compared with the classical annihilation rate. A remarkably strong variation in the onset temperature for tunneling and the lifetime of the skyrmion is found as a function of the values of parameters in the extended Heisenberg Hamiltonian, i.e. the out-of-plane anisotropy, Dzyaloshinskii–Moriya interaction and applied magnetic field. Materials parameters and conditions are identified where the onset of tunneling could be observed on a laboratory time scale. In particular, it is predicted that skyrmion tunneling could be observed in the PdFe/Ir(111) system when an external magnetic field on the order of 6T is applied.

AB - Magnetic skyrmions are nano-scale magnetic states that could be used in various spintronics devices. A central issue is the mechanism and rate of various possible annihilation processes and the lifetime of metastable skyrmions. While most studies have focused on classical over-the-barrier mechanism for annihilation, it is also possible that quantum mechanical tunneling through the energy barrier takes place. Calculations of the lifetime of magnetic skyrmions in a two-dimensional lattice are presented and the rate of tunneling compared with the classical annihilation rate. A remarkably strong variation in the onset temperature for tunneling and the lifetime of the skyrmion is found as a function of the values of parameters in the extended Heisenberg Hamiltonian, i.e. the out-of-plane anisotropy, Dzyaloshinskii–Moriya interaction and applied magnetic field. Materials parameters and conditions are identified where the onset of tunneling could be observed on a laboratory time scale. In particular, it is predicted that skyrmion tunneling could be observed in the PdFe/Ir(111) system when an external magnetic field on the order of 6T is applied.

KW - instanton

KW - lifetime

KW - skyrmion

KW - tunneling

KW - TRANSITION

KW - STATES

UR - http://www.scopus.com/inward/record.url?scp=85095685488&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/0e2ddce5-d2f4-3026-8852-1beafc8243f1/

U2 - 10.1088/1367-2630/ab9f6d

DO - 10.1088/1367-2630/ab9f6d

M3 - Article

VL - 22

JO - New Journal of Physics

JF - New Journal of Physics

SN - 1367-2630

IS - 8

M1 - 083013

ER -