  Here, we report on the experimental discovery of biskyrmion magnetic
nanodomains at RT and the observation of a biskyrmion-derived topological Hall
effect (THE) in the centrosymmetric hexagonal MnNiGa magnet. Using a phase
reconstruction technique based on a transport-of-intensity equation (TIE), we
established the texture of the biskyrmion spin. Results from Lorentz
transmission electron microscopy (TEM) and the topological Hall effect revealed
that the biskyrmion phase is stable over a much wider temperature range (100 K
to ~340K) and a larger magnetic field range in our material than in
skyrmion-hosting bulk crystals reported previously[1-3,6]. The super-wide
operating temperature and the broad range of material options indicate
important progress toward the realization of skyrmion-based spintronic devices.

Materials Science