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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1478
DTSTART:20090310T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260506T181227Z
LAST-MODIFIED:20090226T200837Z
LOCATION:5310 Chamberlin
SUMMARY:Single-Particle Properties of Graphene: Magnetotransport and S
 uperlattice-Controlled Band Gap\, R. G. Herb Condensed Matter Seminar\
 , Rakesh Tiwari\, Ohio State University
DESCRIPTION:Graphene\, a two-dimensional form of carbon\, is poised to
  play an important role in future electronic devices.  In this talk I 
 will discuss two properties of graphene which may be very useful for n
 ext-generation devices: large magnetoresistance and the controllable b
 and gap at the Dirac point. I will show that the experimentally observ
 ed large magnetoresistance can be explained using a picture of graphen
 e as a mixture of n and p type puddles. Even if we assume a field inde
 pendent resistivity for the individual puddles (free electron or hole 
 picture)\, an effective medium approximation predicts a large  magneto
 resistance for the composite\, in agreement with experiment.  In the s
 econd part of the talk\, I will describe an efficient way of controlli
 ng the electronic band gap at the Dirac point in graphene using a non-
 centrosymmetric superlattice potential.  I will confirm this method by
  calculating the superlattice band structure using an expansion of the
  wave functions in plane waves.
URL:https://www.physics.wisc.edu/events/?id=1478
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