Condensed Matter seminar: "Excitons in Flatland: Exploring and Manipulating Many-body Effects on the Optical Excitations in Quasi-2D Materials"
Diana Qiu, Lawrence Berkeley Laboratory
Since the isolation of graphene in 2004, atomically-thin quasi-two-dimensional (quasi-2D) materials have proven to be an exciting platform for both applications in novel devices and exploring fundamental phenomena…
Condensed Matter seminar: "Strange quantum matter: Fermi surfaces sans Fermi liquids"
Debanjan Chowdhury, Massachusetts Institute of Technology
The concept of electronic quasiparticles, as introduced by Landau, is one of the cornerstones of the theory of quantum many-body systems. However, a growing number of recent experiments in strongly correlated quantum…
Astronomy seminar: "Dark Matter in Disequilibrium"
Mariangela Lisanti, Princeton University
The Gaia mission is in the process of mapping nearly 1% of the Milky Way’s stars. This data set is unprecedented and provides a unique view into the formation history of our Galaxy and its associated dark matter halo…
High Energy Theory seminar: "Holographic Entropy Cone with Time Dependence"
Bartek Czech, Tsinghua University
In the AdS/CFT correspondence, if a CFT state is dual to a semiclassical spacetime, its entanglement entropies (minimal surface areas) must obey certain inequalities. The best-known examples are the strong…
Condensed Matter seminar: "Exploring the Landscape of Complex Quantum States: From New Phases of Matter to Robust Schemes for Quantum Computation"
Ksheerasagar "Sagar" Vijay, Harvard University
We present recent advances in our understanding of (i) exotic quantum phases of matter in three dimensions, and (ii) robust mechanisms for storing and processing quantum information, that have been enabled by new…
Condensed Matter seminar: "Tensor Gauge Theories of Fractons"
Michael Pretko, University of Colorado
A fracton is an unusual new type of emergent quasiparticle, first proposed in the context of quantum spin liquids, which does not have the ability to move by itself. Rather, fractons can only move by forming certain…
Astronomy seminar: "Distances for Cosmology"
Rachael Beaton, Princeton/Carnegie
Distances are the fundamental datum by which we translate observational quantities into astrophysical ones and distances remain difficult to measure. I will describe techniques that use old stellar populations in…
High Energy Theory seminar: "Shift Symmetries in (A)dS"
Kurt Hinterbichler, Case Western Reserve University
I will discuss the generalizations of shift symmetries, galileon symmetries, and extended galileon symmetries to (A)dS space and to higher spin. Unlike flat space, these symmetries are present only for particles…