  The ever-growing demand for device miniaturization and energy efficiency in
data storage and computing technology has prompted a shift towards
antiferromagnetic (AFM) topological spin textures as information carriers,
owing to their negligible stray fields, leading to possible high device density
and potentially ultrafast dynamics. We realize, in this work, such chiral
in-plane (IP) topological antiferromagnetic spin textures, namely merons,
antimerons, and bimerons in synthetic antiferromagnets by concurrently
engineering the effective perpendicular magnetic anisotropy, the interlayer
exchange coupling, and the magnetic compensation ratio. We demonstrate by
three-dimensional vector imaging of the N\'eel order parameter, the topology of
those spin textures and reveal globally a well-defined chirality, which is a
crucial requirement for controlled current-induced dynamics. Our analysis
reveals that the interplay between interlayer exchange and interlayer magnetic
dipolar interactions plays a key role in significantly reducing the critical
strength of the Dzyaloshinskii-Moriya interaction required to stabilize
topological spin textures, such as AFM merons, making synthetic
antiferromagnets a promising platform for next-generation spintronics
applications.
