  The intermetallic Gd2PdSi3 has recently generated a lot of excitement after
reports that it hosts chiral magnetic nano-skyrmions despite its
centrosymmetric crystal structure. Using magnetic-field-dependent polarized
resonant elastic x-ray scattering (REXS), we find than an unexpected
incommensurate charge density wave (CDW) appears below the ordering transition
with a wavevector equal to that of the magnetic textures. Furthermore, we show
these incommensurate magnetic textures in Gd2PdSi3 are highly anisotropic, with
the vast majority of the spin modulation lying within the hexagonal ab-plane.
This observation is not compatible with the previously suggested non-coplanar
magnetic textures and coplanar alternatives are discussed. Our results thus
refute the interpretation of the observed large anomalous Hall and Nernst
effects in Gd2PdSi3 as arising from topologically-nontrivial magnetic
skyrmions.
