Flexoelectricity is an electromechanical phenomenon produced in a dielectric material, with or without centrosymmetric microstructure, undergoing non-uniform strain. It characterized by the fourth-order flexoelectric tensor, which links electric polarization vector gradient of second-order strain tensor. Our previous work [H. Le Quang and Q.-C. He, Proc. R. Soc. A 467, 2369 (2011)] solved funda...

In the present work third-order nonlinear optical (NLO) properties of complex-oxides crystals, including absorption (NLA) and refraction (NLR) are performed by Z-scan technique. The non-centrosymmetric lithium niobate (LiNbO3) tantalite (LiTaO3) centrosymmetric cadmium tungstate (CdWO4), calcium (CaWO4) molybdate (CaMoO4) single crystals were used for experimental investigation. main parameters...

We theoretically investigate the origin of square-type skyrmion crystal in centrosymmetric itinerant magnets, motivated from recent experimental finding GdRu$_2$Si$_2$ [N. D. Khanh $\mathit{et}$ $\mathit{al.}$, Nat. Nanotech. $\mathbf{15}$, 444 (2020)]. By simulated annealing for an effective spin model derived Kondo lattice on a square lattice, we find that composed superposition two helices i...