Past Events

  • Condensed Matter Seminar: "The Case for an Exciton Metal in Bilayer Graphene"

    David Rittenhouse Laboratory, A4

    Michael Zaletel (Princeton University)

    Graphene based heterostructures have emerged as a pristine platform for exploring the interplay of symmetry, topology and non-Abelian excitations in the quantum Hall regime. I will begin with a theoretical review of the quantum Hall effect in bilayer graphene before discussing results in collaboration with the Young Lab at UCSB. Using in-situ control of the density and electro-magnetic fields, they find a rich phase diagram which features a plateau at half-filling of a Landau level with a gap several times larger than previously observed.

  • High Energy Theory Seminar: (TBA)

    David Rittenhouse Laboratory, 2N36

    Mukund Rangamani (UC Davis)

  • Joint Mathematics & Physics Seminar: 6D SCFTs and Group Theory

    David Rittenhouse Laboratory, 4C2

    Tom Rudelius (IAS)

    Certain classes of superconformal field theories in six dimensions (6D SCFTs) are in one-to-one correspondence with certain classes of group homomorphisms.  In this talk, we will see that this correspondence allows us to classify homomorphisms that were previously unknown in the mathematics literature and understand aspects of 6D SCFTs that were previously unknown in the physics literature.  We speculate on the implications for the future study of 6D SCFTs and these group homomorphisms.

  • Condensed Matter Seminar: "Jamming of non-circular and deformable particles"

    David Rittenhouse Laboratory, A4

    Mark Shattuck (City University of New York)

    We study mechanically stable packings of deformable and rigid 2D circulo-polygons using computer simulations. A 2D circulo-polygon is a particle shape formed by the collection of all points equidistant from the edge of a polygon. It is a generalization of the 2D circulo-cylinder and a circle, which are the collections of all points equidistance from a line and a point, respectively. In our model, the circulo-polygon can be deformable, where the only constraint on the particle is that shape factor, the ratio of the area of the polygon to the square of the perimeter, is fixed.

  • Astro Seminar: "Cosmology with Galaxy Clusters: from Weighing the Giants to LSST"

    Anja von der Linden (Stony Brook)

    Surveys of galaxy clusters provide a sensitive probe of cosmology by measuring the evolution of the halo mass function. However, already current cluster surveys are systematically limited by uncertainties in the relation between cluster mass and observables (e.g. X-ray luminosity, cluster richness, SZ decrement). Cluster weak lensing is the most promising observational method to calibrate the mass scaling to the needed precision but requires the control of systematic errors to a few percent each.

  • Physics Department Colloquium: Eye patches: The Evolution of Novel Soft Matter

    David Rittenhouse Laboratory - A8

    Alison Sweeney (U of Penn)

    Life on Earth constitutes the most sophisticated iterations in the known universe of what physicists classify as soft matter.  Research in my group focuses on learning the physical rules of soft matter self-assembly phenomena via the evolutionary processes by which they arose over Earth’s history.  In this view of life as soft matter, evolution, with its own formal rules and algorithms, governs the appearance and diversification of novel forms of soft matter.  The field of soft matter was until very recently restricted to analytical consideration of simpler systems like isotr

  • HET & HEE Joint Seminar: "Applications of the Average Null Energy Condition"

    Center for Particle Cosmology

    Clay Cordova, (IAS Princeton)

    Local energy conditions are the key hypothesis in many classical results in general relativity.  In quantum theory, these local energy conditions are invalidated due to quantum fluctuations.  Nevertheless a weaker condition, the so-called average null energy condition still holds in quantum field theory. I will explain how this condition constrains the data of conformal field theories such as operator product coefficients and scaling dimensions.

  • Dissertation Defense: "Electronic Properties of Grain Boundaries in Single Layer Graphene"

    David Rittenhouse Laboratory, 4C8

    Madeleine Phillips (UPenn)

  • Condensed Matter Seminar: "Advanced Electron Microscopy Approaches for Condensed Matter Research"

    David Rittenhouse Laboratory, A4

    Eric Stach (University of Pennsylvania)

    In the next year, the Singh Nanotechnology Center will install two new scanning transmission electron microscopes that will bring Penn’s capabilities in atomic scale materials characterization to a world leading level.  In this seminar, I will describe these capabilities using examples from my own research, from the literature and I will include the latest available results from the instrument manufacturers.  This seminar will be deliberately forward looking and is intended to inform the Penn Condensed Matter community of the full scope of capabilities so that they may pla


    DRL, A1


    Examinations that are postponed because of conflicts with other examinations, or because more than two examinations are scheduled in the same day, may be taken at another time during the final examinations period for if the faculty member and student can agree on that time. Otherwise, they must be taken during the official period for postponed examinations.