# Conformal field theories and quantum phase transitions: an entanglement perspective

Date: Wed, Sep 30, 2020

Location: Zoom, University of Sasktachewan

Conference: quanTA CRG Seminar

Subject: Mathematics, Physics, Condensed Matter and Statistical Mechanics, Particle Physics and Quantum Field Theory

Class: Scientific

CRG: Quantum Topology and its Applications

### Abstract:

Quantum phase transitions occur when a quantum system undergoes a sharp change in its ground state, e.g. between a ferro- and para-magnet. I will present a remarkable set of transitions, called quantum critical, that are described by conformal field theories (CFTs). I will focus on 2 and 3 spatial dimensions, where the conformal symmetry is powerful yet less constraining than in 1 dimension. We will probe these scale-invariant theories via the structure of their quantum entanglement. The methods will include large-N expansions, the AdS/CFT duality from string theory, and large-scale numerical simulations. Finally, we’ll see that certain quantum Hall states, which are topological in nature, possess very similar entanglement properties. This hints at broader principles that relate very different quantum states.

For other events in this series see the quanTA events website.