Observation of spin chirality in a SrRuO3 superlattice

SrRuO3 (SRO), a well-known ferromagnet, has been gaining recent attention as a candidate semimetal in which elementary excitations are relevant to the Weyl fermionic state [1]. An existing chiral spin structure in a single-layered ultra-thin SRO film on a SrTiO3 (STO) substrate was recently demonstrated by resonant soft x-ray scattering (RSXS) [2]. More recent success of well-engineered epitaxial SRO/STO superlattices (SLs) growth enables us to explore precise observation of minute changes in the lattice dynamic and corresponding spin structure in the SRO layer [1,3,4]. In this regard, we performed RSXS at the oxygen K-edge to study an SRO/STO SLs under a magnetic field (0.4 Tesla) along the sample surface and observed a chiral spin structure. We further compared the spin structure among the SRO thin film and SLs. We found that forming the chiral spin structure is critical to the interface effect between the SRO and the STO. More detailed spin configurations will be discussed in the presentation. We believe that these findings would be helpful for tailoring a spin structure and its precise control in spin-engineering applications.