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CATEGORIES:Academics,Faculty & Staff,Grad Students & Postdocs,College of Ar
 ts and Sciences
DESCRIPTION:"Emergent Pseudo-Gauge Field and Gravitational Field in Dirac M
 aterials" \n\n \n\nPresented by Dr. Chaoxing Liu\, Professor\, from Pennsyl
 vania State University\n\n \n\nElectrons in solids are usually described by
  non-relativistic Schrödinger equation since electron velocity is much slow
 er than the speed of light. However\, the relativistic Dirac equation can e
 merge as a low energy effective theory for electrons in certain solid mater
 ials. These systems are dubbed “Dirac materials” and provide a tunable plat
 form to test quantum relativistic phenomena in table-top experiments. More 
 interestingly\, different types of perturbations in these Dirac materials\,
  such as lattice vibration\, strain\, magnon and material inhomogeneity\, c
 an be coupled to relativistic electrons in a similar form as the gauge fiel
 d or gravitational field. We thus dubbed these types of perturbations as th
 e emergent background “pseudo-gauge field” or “gravitational field” in Dira
 c materials. In this talk\, I will focus on electron-strain coupling in Dir
 ac materials by treating the strain (or equivalently acoustic phonons) as e
 mergent pseudo-gauge field or gravitational field. This viewpoint allows us
  to theoretically predict rich physical phenomena in Dirac materials\, incl
 uding (1) piezo-electric and piezo-magnetic response in 2D or 3D Dirac mate
 rials [Nat. Commun. 11\, 2290 (2020)\; PRB 104\, 174406 (2021)]\; (2) phono
 n helicity\, namely the “helical texture” of phonon angular momentum\, indu
 ced by electron Berry curvature in 2D massive Dirac materials [PRL 127\, 12
 5901 (2021)] or Nieh-Yan anomaly of Weyl fermions in 3D chiral crystals [PR
 B 106\, 115102 (2022)]\, (3) and localized phonon modes at the surface/inte
 rface of 3D Dirac materials\, induced by the axion electrodynamical respons
 e or Nieh-Yan gravitational response of 3D massive Dirac fermions [PRB 110\
 , L161301 (2024)].
DTEND:20251014T193000Z
DTSTAMP:20260315T092805Z
DTSTART:20251014T183000Z
GEO:39.681038;-75.752869
LOCATION:Sharp Lab\, 215
SEQUENCE:0
SUMMARY:CMP Seminar - Dr. Chaoxing Liu
UID:tag:localist.com\,2008:EventInstance_50879623012831
URL:https://events.udel.edu/event/cmp-seminar-dr-chaoxing-liu
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