Quantum Matter/QFT/Condensed Matter/Math CMSA seminar - Shared screen with speaker view
Juven Wang
[Cond-Matter/Math July 9th, Thur 9 -10:30 am] Debanjan Chowdhury (Cornell) - Deconfined metallic quantum criticality-I - on Harvard CMSA ZOOM 977347126
Juven Wang
Deconfined metallic quantum criticality-I
 Debanjan Chowdhury (Cornell)
Juven Wang
A number of strongly correlated electronic materials exhibit quantum criticality that does not fit into the conventional Landau-Ginzburg-Wilson paradigm of continuous phase transitions. Inspired by these experimental examples, I will discuss a new class of quantum phase transitions that describe a continuous transition between a Fermi liquid metal with a generic electronic Fermi surface and electrical insulators without Fermi surface of neutral excitations. Such phase transitions are described in terms of a finite density of fractionalized excitations coupled to emergent gauge fields. I will discuss various concrete examples of such gauge theories and describe their associated phase transitions using a renormalization group framework.
Juven Wang
Remarkably, we find examples of continuous phase transitions between Landau Fermi liquid metals and insulators, where the quantum critical point hosts a non-Fermi liquid with a sharp Fermi surface but no long-lived quasiparticles. I will comment on the relevance of this new theoretical framework for some of the most pressing questions in the field of quantum matter
Stephen J. Watson
Can someone remind me what W & U are here?
Elio Koenig
Bandwidth and on-site interaction, I assume.
Stephen J. Watson
@Elio Thanks
Stephen J. Watson
What parameters are being varied here to drive these transitions? Is it around $r=0$
Stephen J. Watson
The condition \nu >2/3 is associated with which range of parameters
Stephen J. Watson
Thank you
Stephen J. Watson
I missed something here. What is the overarching Field Theory for which this is the low energy theory?
One question: For spin 1/2 model, Can B really be in a trivial Mott insulator? Given that it carries both charge and spin, do we need to worry that it needs to be in a spin-liquid insulator?
Eslam Khalaf
The theory has a non-Abelian Chern-Simons term. right? wouldn't this gap out the gauge bosons and render the pairing interaction short-ranged?
Juven Wang
We can hear Debanjan