Microstructured Quantum Matter Department

Director: Philip Moll

For decades, silicon has been the cornerstone  of modern  electronics. Its  reliability and  versatility have made possible the information age we live in today. Yet, as powerful as silicon is, it represents only a narrow slice of what the quantum world has to offer. The  future  will  not  be  about  replacing  silicon, but  about  enhancing it with new materials whose electronic properties open entirely different possibilities.

This is where the field of quantum materials  comes in. In these systems, the behavior of  electrons  goes  beyond  the classical picture of charged particles moving through a lattice.  Instead, quantum mechanics becomes directly visible: electrons reveal their wave-like nature, producing effects such as coherence, interference, and entanglement that shape the material’s properties. These are not just theoretical curiosities  —  they  create  avenues  for  new  functionality, from dissipationless transport to exotic magnetic states and unconventional superconductivity.

A central theme in  our  research is  that in such  materials, geometry  matters. Unlike  in  silicon-based  devices,  where shape mainly sets the scale of a circuit,  in  quantum  materials  the  very size and  three-dimensional  architecture  of a crystal can determine how quantum states form and evolve. The boundaries of a conductor act like mirrors for electron waves, and by controlling these boundaries, we can tune the quantum behavior itself.

Our group therefore pioneers nanometric control of single crystals of complex compounds, sculpting them into unique mesoscopic 3D structures by using Focused Ion Beam techniques. By doing so, we create model systems in which the interplay between quantum mechanics and geometry becomes directly observable.

We explore this paradigm across a wide spectrum of quantum matter, including:

• Topological semimetals, where exotic surface states emerge from nontrivial band topology.
• Strongly correlated systems, such as heavy fermions and unconventional superconductors, where interactions between electrons dominate their behavior.
• High-temperature superconductors, which still challenge our understanding of quantum coherence.
• Ultrapure ballistic & hydrodynamic metals, where electrons transition between single particle and collective hydrodynamic transport.
• Complex magnets, whose competing orders lead to novel excitations.

Through these efforts, we aim to uncover general principles of how electrons organize in complex quantum systems— and   how   the  shape   of  matter   itself  can significantly  steer  their  properties.  Our  work  not  only  provides  new   insights  into  the  foundations  of condensed  matter  physics,  but  also  points  to  the   design  strategies  for  future  electronics,  where functionality emerges from the union of chemistry, quantum mechanics, and geometry.

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