Christian Roos is a Senior Scientist at IQOQI Innsbruck, where he is leading three trapped-ion experiments on quantum simulation, quantum logic spectroscopy and the use of picosecond laser pulses for fast entangling gate operations. Among his widely recognized achievements are the analysis and implementation of high-fidelity entangling gates and their application to quantum information and simulation, and innovative ways of using entanglement for precision measurements. At the moment, his research team consists of 5 PhD students and 2 postdocs. The group is currently performing experiments simulating spin models with strings of up to 20 ions, working on a quantum-logic based optical frequency standard and investigating fast quantum operations. ESQ postdocs interested in quantum control of complex systems at the single-particle level will find a research area requiring technical skills in fields like laser physics, trapping techniques, or experiment control, as well as familiarity with concepts from quantum information and quantum optics.