In the last decade, and starting with the seminal report of electronic conductivity in the domain walls of multiferroic BiFeO3 there has been an intense research effort on the physical properties of domain walls -the boundary between different configurations of the order parameter in a ferroic material. Domain walls and phase boundaries (the interfaces between different phases of the same material) are seen as devices themselves, after Herbert Kroemer's proposal for semiconductor interfaces, with the crucial advantage over 'standard' interfaces that domain walls and phase boundaries can be created, annihilated, and moved with an external field. In this respect, it is considered a key understanding, besides internal functional properties, their dynamics and motion control
My research focuses on two main lines. The first one explores domain-wall motion under external fields, while the second one aims to study dynamical properties of the ferroic order. Both lines share a common goal, which is the control of the domain wall motion. In other words, the objective is to change the intrinsic non-predictable domain motion to a predictable behaviour in a reversible way. The idea is to tune the avalanche behaviour of the domain-wall motion through a perturbation of the order parameter. Taking into account that the domain walls have typically a width of few unit cells, the precision needed when moving it should not exceed the nanometer scale or at least largely reduce the probability of having large jumps. Having the control of the domain wall position will fill out the scenario of domain-wall engineering where the domain walls are the device itself. In addition, that could eventually impact on the neuromorphic computing field, where the criticality has an impact on the learning and the performance.
