Spin dynamics in 3D and 2D

Solid state spin systems show dynamic processes over a wide rage of timescales. With the invention of well-controlled spin structures, the phase behavior and spin dynamics can be controlled and changed in great detail. In the talk, I will discuss the spin dynamics in small scale spin clusters in 3D spin systems. I will then compare our findings to strictly 2D spin layers, exemplified by nuclear spins in hexagonal boron nitride monolayers. Furthermore, I will show the application of a quantum sensor to measure phases and structure of correlated electron materials. Prominent examples are measurements on two-dimensional spin systems showing ferro- or antiferromagnetic spin order. Phase transitions and novel phases by combining two-dimensional layers with different spin orders can be detected.