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Quantum Matter/QFT/Condensed Matter/Math CMSA seminar - Shared screen with speaker view
Juven Wang
40:36
[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
00:40:44
Deconfined metallic quantum criticality-I
 Debanjan Chowdhury (Cornell)
Juven Wang
40:54
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
41:00
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
57:56
Can someone remind me what W & U are here?
Elio Koenig
58:17
Bandwidth and on-site interaction, I assume.
Stephen J. Watson
58:32
@Elio Thanks
Stephen J. Watson
01:13:13
What parameters are being varied here to drive these transitions? Is it around $r=0$
Stephen J. Watson
01:16:27
The condition \nu >2/3 is associated with which range of parameters
Stephen J. Watson
01:17:41
Thank you
Stephen J. Watson
01:49:29
I missed something here. What is the overarching Field Theory for which this is the low energy theory?
Yahui
01:59:48
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
02:03:28
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
02:08:25
We can hear Debanjan