Fig. 6: Skyrmion bundles comprise skyrmion tubes encircled by a fractional Hopfion.
From: Stable skyrmion bundles at room temperature and zero magnetic field in a chiral magnet
a Simulated 3D magnetic configurations of skyrmion bundles. The iso-surfaces correspond to different values of the normalized out-of-plane magnetization component mz. b Simulated magnetic iso-surfaces of the Q = 0, 1, 2, and 3 bundles for mz = 0.9. The colorwheel represents the in-plane magnetizations.
