Microstructured Quantum Matter Department

Director: Philip Moll

The extraordinary success of Silicon has formed the technological developments for the past century. Looking ahead, the dominance of this material is being challenged from multiple angles. The Moore’s law scaling promising ever increasing transistor density is hitting fundamental limits. Yet also the urgent need to reduce the power consumption as well as the developments towards quantum information calls for materials beyond semiconductors and classical metals. While the need for new materials is clear, the perfection of state-of-the-art silicon creates a high entry barrier for them.

Here at the department for microstructured quantum matter, we work on prototyping advanced functionalities that novel materials promise tomorrow with the actual materials available today. Our department is interested in materials in which electrons fundamentally behave differently than in Copper or Silicon. The broad term “quantum materials” was coined for such situations, including strongly correlated electron systems, topological conductors, quantum magnets, unconventional and high-temperature superconductors, heavy-fermion materials and many more. Unlike commercial Silicon wafers of extreme perfection, these materials are at the forefront of physical chemistry and the synthesis of high-quality crystals can be extremely challenging. We develop fabrication schemes to turn even microscopic crystallites of these complex compound materials into micro- and nano-structures of highest quality and study their electronic and magnetic properties. The workhorse tool of our technique is the Focused Ion Beam, which allows us to carve crystalline circuits out of these particles with nanometric precision. The electronic response of these microstructures are probed by charge transport experiments, at cryogenic and dilution-refrigerator temperatures and in high magnetic fields up to 20T. Close collaborations with pulsed field facilities extends the range of available fields into the 100T range.

With this approach, we go beyond the possibilities of static crystals and tune the quantum states of these materials in extreme and non-linear ways. Most prominently, we apply controlled strain and strain gradients to quantum materials which are impossible to achieve on the macro scale. This allows us to tune correlation landscapes, channel density waves, or create artificial gauge fields in solids. Ultrafast quenching and extreme non-linear currents modify the electronic spectrum and induce novel, meta-stable quantum states.

Our young and active department is always looking for highly motivated students and scientists to join our scientific journey.