Back to Listing

Institute for Condensed Matter Theory Seminar: "Strange metals as ersatz Fermi liquids: emergent symmetries, anomalies, and experimental tests"

Event Type
The Institute for Condensed Matter Theory
via Zoom
Oct 26, 2020   12:00 pm  
Senthil, Massachusetts Institute of Technology
Originating Calendar
Physics - Institute for Condensed Matter Theory Seminar

Despite decades of work, strange metals that defy Fermi liquid theory challenge our understanding. In this talk I will discuss properties of  such  phases of matter in systems with a global U(1) symmetry and  discrete translation symmetries.    I will show that  the low-energy theory must have a very large emergent symmetry group -- larger than any compact Lie group. I will  revisit standard Fermi liquid theory from a modern point of view of characterizing its emergent symmetry and its associated 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). Such phases - dubbed ersatz Fermi liquids -  share some (but not all) universal properties with Fermi liquids. I will discuss the implications for understanding the famous ``strange metal" physics observed in experiments in some condensed matter systems. Combined with a few experimental observations, I will show that these general model-independent considerations lead to concrete predictions about a class of strange metals. The most striking of these is a divergent susceptibility of an observable that has the same symmetries as the loop current order parameter. 

link for robots only