Abstract Submission Deadline December, 1st 2016
Every year at the DPG spring meeting a group of PhD students has the chance to organize a symposium on a topic they are interested in. In this framework a group of five PhD students from the Technical University Braunschweig will organize a Symposium on frustrated quantum magnets at the next DPG spring meeting in 2017 in Dresden.
Quantum magnetism is a very active area of condensed matter physics. In the last decades, this fascinating field has highly profited from the fruitful interplay of experiment and theory. It is a genuinely interdisciplinary area of research, linking across many different subfield boundaries, ranging from condensed matter and statistical physics, via ultra cold atomic gases, spin- and heat caloritronics, classical and quantum information theory, to questions in material design and device technology.
Frustrated quantum magnets can be realized in spin systems in which localized magnetic moments interact through competing exchange interactions that cannot be simultaneously satisfied. Such spin systems may be frustrated due to a multitude of reasons, e. g., quantum chemistry can lead to competing exchange paths or lattice geometry can induce frustration. Furthermore, spin-orbit interactions may lead to pseudo-spins with frustrating compass interactions and higher-order exchange can generate frustration through ring exchange. On the classical level frustration gives rise to a large degeneracy of the system’s ground state. Frustration occurs due to geometrical reasons or higher order exchange processes. On the quantum level this might lead to the emergence of unconventional solid and liquid phases with exotic excitations. In this context, the possibility of spin liquids is quite interesting from a theoretical as well as from an experimental point of view. While in early days spin liquids have merely been considered to be magnets which lack any type of long range order down to T=0, it has only been realized very recently that such liquids are a novel form of correlated matter which shows topological order and intimately linked to that, fractionalized excitations. In theory, the formation of such matter defies a description in terms of standard Ginzburg-Landau theory and it seems fair to say, that its physics is far from being understood. In experiment, first potentially promising candidates may have been synthesized, such as e. g. triangular magnets in organics, quantum spin ice on pyrochlores, and Kitaev model variants in iridates. Yet, the search for definite materials is still ongoing.
All in all, the study of frustrated quantum magnets reveals new physics and generates contributions to the development of novel materials. The investigation of quantum magnets is however a challenging problem. On the theoretical side numerous sophisticated methods have been developed and applied to gain insight into the properties of spin models, e. g. emergent gauge, and topological field theories, DMRG methods, tensor networks, variational Monte-Carlo and others. On the experimental side extensive material design has to be combined with a multitude of state-of-art probes, like nuclear magnetic resonance (NMR) and muon spin resonance (mu-SR), RIXS, INS, Raman, electron and tunneling spectroscopies as well as transport, high magnetic field, and thermodynamic measurements in order to identify potentially interesting compounds.
For the PhD symposium 2017, the following invited speakers are already confirmed :
- Bruce D. Gaulin, McMaster University, Hamilton, Canada
- Philippe Mendels, University of Paris-Sud, Orsay, France
- Natalia Perkins, University of Minnesota, USA
- Stephan Rachel, TU Dresden, Germany
- Matthias Vojta, TU Dresden, Germany
- Vivien Zapf, National High Field Laboratory, Los Alamos, USA
This symposium is divided into three sessions. The first session is chosen to give an overview about frustrated quantum magnets and topological matter. Therefore, world's leading experts are invited to give two tutorials on theory as well as on experimental aspects. The second session focuses on the theoretical research of quantum magnets with two invited talks and one contributed talk. After the lunch break the session continues with two focused research talks with a representative selection of recent experimental highlights and another selected contributed talk. Finally, students are invited to present and discuss their research within a poster session.
The symposium will presumably take place on 21st March 2017 (yet to be announced) from 9:30 am to 4 pm.
| Welcome and Introduction
| Tutorial Session
| 09:40 - 10:20
|| M. Vojta
|| Frustrated Quantum Magnets: Theory
| 10:20 - 11:00
|| B. Gaulin
|| Frustrated Quantum Magnets: Experiment
| 11:00 - 11:15
|| Coffee break
| Theory Session
| 11:15 - 11:45
|| N. Perkins
|| Models and Mechanisms of Magnetic Frustration
| 11:45 - 12:15
|| S. Rachel
|| Numerical Approaches to Quantum Magnets
| 12:15 - 12:30
|| Contributed Talk (TBA)
| 12:30 - 13:30
|| Lunch break
| Experimental Session
| 13:30 - 14:00
|| P. Mendels
|| Nuclear Probes on Frustrated Magnets
| 14:00 - 14:30
|| V. Zapf
|| High Magnetic Field Phenomena in Quantum Magnets
| 14:30 - 14:45
|| Contributed Talk (TBA)
| 14:45 - 16:00
|| Poster Session
Call for abstracts
As this year's program includes two contributed talks as well as a poster session, we would like to encourage all scientists and students working in this specific or related field to hand in their abstract for a talk or poster contribution. The abstracts can be submitted via the DPG homepage (select MA: Magnetism Division and Topic: PhD Symposium: Quantum Magnets) until December 1st.