Moiré engineering of electronic phenomena in correlated oxides

X. Chen, X. Fan, L. Li, N. Zhang, Z. Niu, T. Guo, S. Xu, H. Xu, D. Wang, H. Zhang, A. S. McLeod, Z. Luo, Q. Lu, A: J. Millis, D. N. Basov, M. Liu and C. Zeng

Nature Physics 16, 631 (2020)
Moiré engineering has recently emerged as an effective approach to control quantum phenomena in condensed matter systems. In van der Waals heterostructures, moiré patterns can be formed by lattice misorientation between adjacent atomic layers, creating long-range electronic order. Moiré engineering has so far been executed solely in stacked van der Waals multilayers. Here we describe electronic moiré patterns in films of a prototypical magnetoresistive oxide, La0.67Sr0.33MnO3, epitaxially grown on LaAlO3 substrates. Using scanning probe nanoimaging, we observe microscopic moiré profiles attributed to the coexistence and interaction of two distinct incommensurate patterns of strain modulation within these films. The net effect is that both the electronic conductivity and ferromagnetism of La0.67Sr0.33MnO3 are modulated by periodic moiré textures extending over mesoscopic scales. Our work provides a potential route to achieving spatially patterned electronic textures on demand in strained epitaxial materials.