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