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UID:UW-Physics-Event-1554
DTSTART:20090924T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260417T151544Z
LAST-MODIFIED:20090916T153555Z
LOCATION:5310 Chamberlin Hall
SUMMARY:Biot-Savart correlations in layered superconductors\, R. G. He
rb Condensed Matter Seminar\, Kumar Raman\, University of California -
Riverside
DESCRIPTION:We discuss the superconductor to normal phase transition i
n an infinite-layered type-II superconductor in the limit where the Jo
sephson coupling between layers is negligible. We model each layer as
a neutral gas of thermally excited pancake vortices. We assume the dom
inant interaction between vortices in the same and in different layers
is the electromagnetic interaction between the screening currents ind
uced by these vortices. Our main result\, obtained by exactly solving
the leading order renormalization group flow\, is that the phase trans
ition in this model is a Kosterlitz-Thouless transition despite being
a three-dimensional system. While the transition itself is driven by t
he unbinding of two-dimensional pancake vortices\, an RG analysis of t
he low temperature phase and a mean-field theory of the high temperatu
re phase reveal that both phases possess three-dimensional correlation
s. An experimental consequence of this is that the jump in the measure
d in-plane superfluid stiffness\, which is a universal quantity in 2d
Kosterlitz-Thouless theory\, will receive a small non--universal corre
ction (of order 1% in Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$). This overall pic
ture places some claims expressed in the literature on a more secure a
nalytical footing and also resolves some conflicting views.
\n
\nReference: Phys. Rev. B 79\, 174528 (2009)\, arXiv:0902.1547
URL:https://www.physics.wisc.edu/events/?id=1554
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