Title of the project: Tension-free Dirac strings and unbound magnetic charges in 3D artificial spin-ice
Name of the VDSP student: Florian Slanovc
Project supervised by: Dieter Süss, Claas Abert

As a 2nd year PhD student in the group Physics of Functional materials, I am working on field calculation and optimization of magnetic materials. Together with the master student Sabri Koraltan, we initiated the investigation of these ice-lattice-like structures. Since this frosty topic fits perfectly to the already winterly temperatures in Vienna, we enjoy debating about it in the frequent coffee break web meetings of our group. Besides work, I love reading novels, jogging, playing chess and also the handful of other activities that are still allowed during the Corona lock-down.

Artificial spin-ices are frustrated mesoscopic ice crystal structures consisting of magnetic elements. In their ground state, the magnetization within the lattice usually obeys the ice rule, i.e. at each vertex the sum of magnetic moments pointing in and out is equal. If the magnetization of one element is reversed, we observe an excess of magnetic field lines at the center of this vertex, which can be regarded as an emergent magnetic monopole and the trace of flipped magnetic elements as a Dirac string. In our work we present a perfectly frustrated 3D artificial spin-ice-lattice, which hosts unbound magnetic monopoles and tension free Dirac-strings. Via micromagnetic simulation we furthermore demonstrate that these quasi monopoles can be propagated through the lattice by applying a global external magnetic field in the appropriate direction.

Süss group