  We investigate the inversion process of magnetic domain walls (DWs)
propagating through synthetic noncollinear magnetic textures, whereby an
up/down DW can be transformed into a down/up DW and vice versa. We exploit the
lateral coupling between out-of-plane and in-plane magnetic regions induced by
the interfacial Dzyaloshinskii-Moriya interaction in Pt/Co/AlOx trilayers to
realize both field-driven and current-driven magnetic DW inverters. The
inverters consist of narrow in-plane magnetic regions embedded in out-of-plane
DW racetracks. Magnetic imaging and micromagnetic simulations provide insight
into the DW inversion mechanism, showing that DW inversion proceeds by
annihilation of the incoming domain on one side of the in-plane region and
nucleation of a reverse domain on the opposite side. By changing the shape of
the in-plane magnetic region, we show that the DW inversion efficiency can be
tuned by adjusting the ratio between the chiral coupling energy at the inverter
boundary and the energy cost of nucleating a reverse domain. Finally, we
realize an asymmetric DW inverter that has nonreciprocal inversion properties
and demonstrate that such a device can operate as a DW diode. Our results
provide input for the versatile manipulation of DWs in magnetic racetracks and
the design of efficient DW devices for nonvolatile magnetic logic schemes.
