Johannes Gutenberg University Mainz > Faculty 08 > Physics > Physics Research > Research Areas > Quantum Matter & Spintronics
When particles in many-body systems begin to interact on a quantum mechanical level, things get exciting—far beyond the predictions of classical physics. Quantum materials are specially designed systems that exhibit exotic electronic, magnetic, and optical properties driven by these collective quantum effects. Their behavior is shaped by the strong interaction with electrons and other excitations such as phonons, magnons, or photons—leading to emergent phenomena that cannot be understood by considering single particles in isolation.
Research in this field pushes the boundaries of both fundamental science and technological innovation. Examples include unconventional superconductors, quantum magnets, quantum spin liquids, topological materials, and complex magnetic orders. One recent breakthrough was the discovery of altermagnets—a new form of magnetic order identified in Mainz—which was recognized as a 2024 Science Breakthrough of the Year.
The next generation of information technology relies on new physical phenomena emerging at the nanoscale, where electron spin, orbits, and charge interact under quantum conditions. Our research explores the fundamental physics and practical applications of spin-based devices through advanced experiments and theoretical modeling. We study spin transport, injection, and manipulation in cutting-edge material systems such as magnetic monolayers, heterostructures, and nanostructures, focusing on the crucial role of interfaces in metals, semiconductors, and oxides. Using an industrially compatible deposition platform, we fabricate and investigate devices featuring magnetic tunnel junctions, spin torques, and quantum electronic effects. Our work spans from basic research at ultra-low temperatures to collaborations with the semiconductor industry, aiming to develop energy-efficient memory, logic, and sensing technologies for future applications in artificial intelligence and beyond.
Driven by mathematical beauty and aesthetics, science often focuses on high-symmetry systems. However, a closer look at nature reveals the ubiquity of broken symmetry, particularly in the form of chirality. Chirality, a fundamental property where objects exist in two non-superimposable mirror images, profoundly impacts material properties. Our research explores the influence of chirality on the electronic and magnetic properties of chiral systems, such as chiral crystals and hybrid chiral molecule-magnetic structures. A key focus is chiral-induced spin selectivity, where a material’s handedness dictates electron spin orientation. Additionally, chiral interactions in magnetic systems stabilize novel, topologically protected spin textures, including skyrmions. By investigating the underlying mechanisms, we aim to unlock the potential for innovative, functional devices that leverage the unique properties of chirality in quantum matter.
Nonequilibrium phenomena occurring on femtosecond to nanosecond timescales can be investigated using table-top femtosecond optical/THz spectroscopy or high-brightness femtosecond X-ray pulses generated at free-electron laser (XFEL) facilities. These advanced techniques provide deep insights into the ultrafast dynamics of electronic, lattice (vibrational), and spin degrees of freedom—enabling us to visualize atomic motion and monitor molecular bond breaking, and to explore the evolution of macroscopic order parameters and light-induced phase transitions.
Our research groups are actively engaged across a broad spectrum of ultrafast science, spanning soft and hard condensed matter, structural biology, and materials science. We operate state-of-the-art ultrafast optical laboratories and maintain a strong presence at XFEL facilities, contributing to both cutting-edge experiments and the development of next-generation end-stations, particularly in the field of time-resolved momentum microscopy.
