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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:4
UID:UW-Physics-Event-5117
DTSTART:20191122T213000Z
DURATION:PT1H0M0S
DTSTAMP:20260415T070734Z
LAST-MODIFIED:20191111T192547Z
LOCATION:2241 Chamberlin Hall
SUMMARY:Looking for excitations with fractional statistics in the quan
 tum Hall regime\, Physics Department Colloquium\, Mike Manfra\, Purdue
  University
DESCRIPTION:The fractional quantum Hall effect (FQHE) occurs when a tw
 o-dimensional electron gas (2DEG) is subjected to a large perpendicula
 r magnetic field at low temperatures. At certain magnetic field values
  determined by the density of the electron gas\, the system forms high
 ly correlated ground states with a gap to low-lying excitations. In th
 ese states\, the transverse Hall resistance is quantized to rational f
 ractions of h/e2 and the longitudinal resistance vanishes. Remarkably\
 , theory predicts that the excitations of the FQHE carry fractional ch
 arge and fractional statistics\, possibly even non-Abelian statistics 
 in certain cases.  The search for “topological” materials with fra
 ctional charge and unusual statistics is currently an exciting branch 
 of condensed matter physics spanning many different physical systems. 
 Here I will describe how we create extremely high quality 2DEGs in AlG
 aAs/GaAs heterostructures using molecular beam epitaxy and the basics 
 of electron transport experiments we use to study them. Building on th
 is knowledge\, I will discuss how we currently attempt to probe statis
 tics in the FQHE via Aharonov-Bohm interference in small electronic Fa
 bry-Perot interferometers. We have recently demonstrated highly cohere
 nt Aharonov-Bohm oscillations in the fractional quantum Hall regime. T
 his result indicates we may have a viable platform for measurement of 
 particle statistics in a condensed matter system.
URL:https://www.physics.wisc.edu/events/?id=5117
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