Exploiting the internal dynamics of inhomogeneous magnetization states for technological and biomedical applications.

The interplay of different interactions gives rise to complex magnetization structures on the nanoscale, like vortices and skyrmions. These structures can display internal inhomogenous dynamics, which is for instance the case in the technologically relevant regime where the driving forces are relatively weak compared to thermal excitations. In this project, we will exploit these inhomogeneous dynamics with the aim to improve a state-of-the-art biomedical and technological application, in which these internal dynamics are unexploited to this day. To reach this aim, we will use a computationally challenging micromagnetic simulation approach, complemented by experimental results obtained within the framework of two international collaborations. 1. In collaboration with PTB Berlin, Germany, we will unravel the relations that describe the heating performance of non-uniformly magnetized nanoparticles with a vortex state (which can be a factor 10 higher than for a uniform magnetization) as function of their structural properties to optimize their use in the cancer therapy “magnetic particle hyperthermia”. 2. In collaboration with MIT, USA, we will realize an efficient driving mechanism for skyrmions, that operates on the rectification of random thermal fluctuations into a directed motion, without any driving currents. These structures are currently considered at the forefront of stochastic logic devices, in which our breakthrough will strongly decrease the power consumption.