The main topics of his research in the last 10 years were strongly correlated electron systems like unconventional superconductors or transition metal oxides. Of special interest were the effects of spin, charge, and orbital correlations in 3-dimensional perovskite systems with partly occupied 3d-electronic levels. The used experimental techniques were inelastic neutron scattering, Raman lights scattering, and resonant inelastic x-ray scattering (ESRF/Grenoble and PSI/Switzerland). The combination of these complementary techniques allowed to yield a detailed insight in the physics behind strongly correlated electron systems.

Clemens Ulrich was the group leader of the Raman laboratories at the Max-Planck Institute in Stuttgart. He was involved in inelastic neutron scattering experiments (triple-axis-spectrometers and time-of-flight spectrometers) and has performed resonant inelastic x-ray scattering experiments at various synchrotron facilities in Europe.

Clemens Ulrich has more than 60 refereed publications in high-impact journals in magnetism, strongly correlated electron materials and condensed matter physics. His publications were cited more than 1350 times and his Hirsch index is 19.