Non-fermi liquids, fixed point collisions, and tensorial order in grey tin and in some popular field theories

Condensed Matter Seminars

Speaker: Igor Herbut, Simon Fraser University
Date & Time: Thu, 2017-10-26 14:00 - 15:00
Location: AMPEL #311
Local Contact: Ian Affleck
Intended Audience: Graduate

Abrikosov proposed in 1974 that a 3D electronic system with its fermi

level at the point of quadratic band crossing, as in the (spin-orbit

coupled) gray tin or mercury telluride, should represent the simplest

non-fermi liquid. I will review this idea and discuss how a non-fermi

liquid ground state may become unstable to ordering via the mechanism of

“fixed-point collision”. This mechanism, with its concomitant hierarchy

of scales, may also be identified as the culprit behind the notorious

dynamical chiral symmetry breaking in the three dimensional

electrodynamics, known as the effective theory of several strongly

interacting condensed matter systems and as a favorite toy model of

particle theorists. Some further applications of the nematic order

parameters, possibly relevant  to gray tin or iridates, in the current

search for  higher-dimensional interacting field theories will also be

mentioned, time permitting.