摘要
The Dzyaloshinskii–Moriya interaction(DMI)is well known to favor a chiral rotation of the magnetic moments,which accounts for the emergence of the skyrmions.The DMI is a combined effect of spin–orbit coupling with broken inversion symmetry in magnets.Most of the noncentrosymmetric magnetic materials that bear skyrmions involve nonmagnetic elements.This work shows that strong DMIs exist in elemental cobalt with a β-Mn-type metastable structure.The variation of DMI among different cobalt pairs largely follows the variation of hopping magnitude in which p electrons play an important role.Although the DMIs between different atomic pairs partly cancels with each other,the net interaction is sufficient to result in a left-handed Bloch-type spiral.Spin dynamics simulation shows that a critical magnetic field of 2.9 T stabilizes skyrmions at 0 K.
基金
We acknowledge the financial support from the Ningbo Scientific and Technological Project under Grant No.2011B82004 and NSFC under Grant No.51401227.H.B.L acknowledges the continuous support of computing resource from CCMS of the IMR in Tohoku University
J.P.L thanks US/DoD/ARO support under grant W911NF-11-1-0507
H.B.L thanks Gideon Müller from Forschungszentrum Jülich and JARA for offering help to use the SPIRIT code.
