Workshop Outcomes

NSF Frontiers of Experimental Condensed Matter Physics:
CMP Principal Investigators’ Workshop on Topological Phases of Matter 

Princeton University, supported by the Condensed Matter Physics Program in the Division of Materials Research, NSF, hosted a workshop at the Hilton Arlington, VA, adjacent to the NSF headquarters, on May 23 and 24, 2016. The goal of the workshop was to explore topics at the frontier in the investigation of topological phases of matter. The workshop included researchers from universities and national laboratories, and discussions focused on current and emerging trends in the field. 

During the last seven years several new topological phases have been discovered, including topological insulators and topological semimetals. The search for topological superconductors has also experienced major advances by using hybrid systems to engineer topological systems. Each of these topological phases and material systems presents unique opportunities for discovery of new electronic phenomena, and the likelihood that there are yet still new types of topological phases to be discovered. A number of exotic quasiparticles such as Dirac, Weyl, and Majorana fermions have been realized, but there is still room for many more discoveries. One direction that remains mostly unexplored is the search for interacting topological phases and interacting Majorana fermions and parafermion quasiparticles. The meeting fostered collaboration between researchers with different expertise, such as material experts, transport and spectroscopy experimentalists, and theorists focused on both analytical and numerical investigations. Discussions focused on the future challenges in this field, as well as how the community as a whole can better educate the public about the science of topological phases of matter and how to broaden the impact of the field. 

Workshop topics included:

  • Experimental results in topological insulators and topological superconductors
  • Proximity and edge effects
  • Interplay between topology and strong correlation
  • Possible topological states not covered by the classification scheme of non-interacting fermions
  • New materials and topological states (including Dirac and Weyl fermions)
  • Topological insulators emerging from combining non-interacting band theory
  • Topological phases with non-trivial excitations beyond the quantum Hall regime

This smaller, domestic workshop proved to be highly effective in part because of its smaller size as compared to other (international) conferences that include well over one hundred participants. The small group dynamic enabled cross-pollination across the various sub-disciplines of experimental and theoretical topological phases of matter. Attendees were able to collaborate directly with one another, and NSF CMP PIs had the opportunity to interact with DMR program directors and provide feedback relevant to CMP programs. In addition, the smaller group workshop proved to be more cost effective. 

The workshop was attended by 25 (domestic and international) speakers, 8 representatives from NSF and the DOE, and 5 postdocs/graduate students. The primary organizers were Ali Yazdani (Princeton University) and B. Andrei Bernevig (Princeton University).