HET Seminar | Senthil Todadri, Massachusetts Institute of Technology | “Compressible Quantum Matter: General Constraints, Emergent Symmetries, and Anomalies” | via Zoom

Mon, Oct 12, 2020, 2:30 pm
via Zoom

Abstract: I will discuss properties of phases of matter in systems with a global U(1) symmetry and a (possibly discrete) translation symmetry. 

The low energy theory of such systems is strongly constrained by these symmetries. I will give a framework to understand such constraints in great generality, vastly generalizing old theorems.  The most powerful constraint comes about if the system is compressible, in which case  the low-energy theory must have a very large emergent symmetry group -- larger than any compact Lie group.  A familiar example is a Landau  Fermi liquid, whose properties I will  revisit from a modern point of view of characterizing its emergent symmetry and the associated 't  Hooft anomaly.  Many, if not all, non-Fermi liquids will have the same emergent symmetry group/anomaly as a Fermi liquid (even though they could have very different dynamics), and this determines some of their universal properties. I will discuss the implications for understanding the famous "strange metal" physics observed in experiments in some condensed matter systems.

To connect to the HET Seminar via Zoom, please click the following link:
Meeting ID: 924 6779 0530