  Magnetic Bloch points (BPs) are highly confined magnetization configurations,
that often occur in transient spin dynamics processes. However, opposing
chiralities of adjacent layers for instance in a FeGe bilayer stack can
stabilize such magnetic BPs at the layer interface. These BPs configurations
are metastable and consist of two coupled vortices (one in each layer) with
same circularity and opposite polarity. Each vortex is stabilized by opposite
sign Dzyaloshinskii-Moriya interactions. This stabilization mechanism
potentially opens the door towards BP-based spintronic applications. An open
question, from a methodological point of view, is whether the Heisenberg (HB)
model approach (atomistic model) as to be used to study such systems or if the
-- computationally more efficient -- micromagnetic (MM) models can be used and
still obtain robust results. We are modelling and comparing the energetics and
dynamics of a stable BP obtained using both HB and MM approaches. We find that
an MM description of a stable BP leads qualitatively to the same results as the
HB description, and that an appropriate mesh discretization plays a more
important role than the chosen model. Further, we study the dynamics by
shifting the BP with an applied in-plane field and investigating the relaxation
after switching the filed off abruptly. The precessional motion of coupled
vortices in a BP state can be drastically reduced compared to a classical
vortex, which may be also an interesting feature for fast and efficient
devices. A recent study has shown that a bilayer stack hosting BPs can be used
to retain information [1].
