Tuning Electronic Quantum Materials

Electronic Quantum Materials are characterised by strong interactions between electrons giving rise to exciting new phenomena and properties. For instance, many ordered states are formed due to the electronic interactions including superconductivity and magnetism. Such states are the basis for applications like magnetic resonance imaging used in medicine. We use measurements of magnetic, thermodynamic, and electronic bulk properties whilst tuning the materials in extreme conditions of high pressure, large magnetic fields, and low temperatures to unravel the mechanism and underlying electronic interactions. The comparison of our results with models and theories contributes to a better understanding and may provide the basis for future applications.
In my talk, I will present an overview of our studies of electronic quantum materials ranging from magnetic phase transitions at zero temperature to high-temperature superconductivity at high pressures. For instance, we have discovered a new class of magnetic phase transitions at zero temperature: a so-called quantum tricritical point giving rise to quantum fluctuations associated with two ordered states1. We demonstrate how this arises in the ferromagnet NbSe2. As another example, I will present results from our high-pressure studies of conventional and unconventional superconductors where we observe peculiar competition between superconductivity and charge order. I will conclude with and outlook including record superconductors with transition temperatures approaching room temperature.