Quantum Ferromagnetism and Related Phenomena

International workshop on Quantum Ferromagnetism and Related Phenomena (May 6-10, 2019)

Scientific Coordinators:

• Dietrich Belitz (University of Oregon, Eugene, USA)
• Manuel Brando (Max-Planck-Institute for Chemical Physics of Solids, Dresden, Germany)
• Andrew Huxley (The University of Edinburgh, Edinburgh, UK)

Organization: Katrin Lantsch (Max-Planck-Institut für Physik komplexer Systeme, Dresden)

The international workshop was held at the MPI-PKS from May 6 to May 10, 2019 and was supported by the Deutsche Forschungsgemeinschaft (DFG). The main purpose of the workshop was to discuss recent advances and open problems in the field of quantum ferromagnetism, with a focus on metallic systems. In addition to the ferromagnetic quantum phase transition proper in both clean and disordered systems, topics covered included competition between different magnetic phases, and the interplay between magnetism and superconductivity.

There were 69 participants - out of which 44 invited speakers - from 15 European and non-European countries with a balanced mixture of well established experts in the field and promising young scientists who were chosen to form a diverse group with respect to gender, seniority, and national origin. Specific topics covered included phase diagrams and types of quantum phase transitions (Taufour, Baenitz, Aronson, Friedemann, Kotegawa, Pourret, Wysokinski, von Löhneysen, Stewart), low-dimensional systems (Kliemt, Yuan), interplay between ferromagnetism and superconductivity (Ishida, Geibel, Braithwaite, Aoki, Butch, de Visser, Knebel, Grosche, Mercaldo), spin dynamics (Janoschek, Niklowitz, Pfleiderer), effects of disorder (T. Vojta, Baumbach, M. Vojta, Sales, Schroeder, Uemura, Fritsch), Lifshitz transitions (Pfau, Betouras), magnetism in exotic fermion systems (Kirkpatrick, Rost, Chubukov), competing magnetic orders (Hayden, Krellner, O'Neill, Krüger), anisotropies (Sokolov, Green, Jesche), spin liquids (Perkins). A related topic covered was the quantum antiferromagnetic transition in a two-dimensional metal (Lee). In addition, A. Chubukov delivered a colloquium on superconductivity induced by quantum critical magnetic fluctuations.

The MPI-PKS provided an ideal environment for stimulating scientific discussions and an exchange of ideas between these various fields. Many of the participants commented to us that they found the meeting enjoyable and of benefit to their research and initiating future collaborations. This was also stimulated by alternative activities like the barbeque dinner and the hiking tour in the Saxon Switzerland National Park.

In addition to the talks, 22 posters were presented, mostly by PhD students and postdocs. Both the talks and the poster session were well attended (more than 80%) also by several colleagues from neighbouring institutions (TU-Dresden, MPI-CPfS or IFW). This led to lively discussions. Even on Friday, the departing day of the workshop, more than 60% of the participants attended the last sessions. Feedback from the participants, both during and after the workshop, was very positive.