Speaker: Multiple Speakers
Time: March 6 - 9, 2013
March 6 – 9, 2013, Max Planck Institute for the Physics of Complex Systems, Dresden
The MPI-PKS workshop “Flat Bands: Design, Correlations, Topology” was held from March 6 – 9, 2013. The primary focus of the workshop was the study of emergent strongly correlated phases of matter in systems that exhibit an extensive degeneracy in the absence of inter-particle interactions. This quenching of kinetic energy leads to non-dispersing energy levels colloquially termed ’flat bands’, in which the efficacy of interactions is enhanced. This leads to interesting phases with both conventional broken symmetries, such as ferromagnets, as well as topologically ordered phases such as lattice versions of fractional quantum Hall states and fractional topological insulators. A flurry of recent numerical observations of fractionalized phases in lattice models with ’topological’ flat bands, has renewed interest in the study of flat bands of electronic insulators. There have also been various proposals to realize and study flat bands in experimental systems, ranging from oxide heterostructures to optical lattices of ultracold fermions with an artificial gauge field. In a different vein, the realization of various frustrated hopping models of ultracold bosons in optical lattices has motivated interest in the rather less well-studied problem of bosons in flat bands. In all these cases, the fundamental role played by correlations simultaneously leads to novel behavior while complicating the understanding of these phases from numerical and analytical approaches. The goal of the workshop was to bring together researchers working on diverse aspects of flat band physics.
In summary, the workshop substantially achieved its stated goal of bringing together a diverse range of participants actively engaged in research on a wider variety of topics within the umbrella of flat band physics. There were several fruitful interactions across the different subtopics represented at the workshop; hopefully, these will stimulate further work and collaborative research in new directions. Participants particularly appreciated the abundant time for discussions that were an integral part of the program, and commented on the insightful discussions that ensued.