Lithography of complex topological structures in ferroic materials

Arbitrary polar rotation in oxide perovskites and spontaneous flux closure domain formationwithin a single material is rarely observed due to the high anisotropy energy inherent to ferroelectrics. Purelyphysical rotation of polarization has only been achieved by flexoelectricity, i.e., structural strain gradients,taking advantage of the coupling of ferroelectric and ferroelastic properties or depolarization field engineeringin thin film heterostructures, which combine ferroelectric and dielectric layers leading to curling behaviour of polarization and the creation of vortices-like structures. Non-trivial topological structures have been discoveredin confined ferroelectric layers within artificially engineered superlattices, altogether providing promisingalternatives for nanoelectronic devices based on negative capacitance, or fast broadband communicationsrequired for the 6G era thanks to intrinsic sub-THz resonances. However, examples on the manipulation ofthese topological structures is scarce and only few of them have been created via electric field litography sofar. Here, we will show advanced ferroelectric lithography methodes that will allow the creation of complextopological structures such as skyrmions, vortices and flux closures on demand.