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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-1378
DTSTART:20090212T160000Z
DURATION:PT1H0M0S
DTSTAMP:20260506T181250Z
LAST-MODIFIED:20090108T142926Z
LOCATION:5310 Chamberlin
SUMMARY:Precision Measurements of the London Penetration Depth and Pai
 ring Symmetry in Superconductors\, R. G. Herb Condensed Matter Seminar
 \, Ruslan Prozorov\, Iowa State University & Ames Laboratory
DESCRIPTION:The pairing mechanism is the Holy Grail for researchers in
  the field of superconductivity. One of the experimentally accessible 
 manifestations of the pairing mechanism is the structure of the superc
 onducting gap on the Fermi surface and the corresponding behavior of l
 ow-energy quasiparticles with respect to an applied magnetic field\, s
 cattering rate\, heat flow\, etc. The London penetration depth is dire
 ctly related to the superfluid density and\, therefore\, is one of the
  primary experimentally measurable quantities. It is also relatively e
 asy to model for various superconducting gaps and for arbitrary scatte
 ring by using microscopic or semiclassical formalisms.<br>
\n<br>
\nDu
 ring the last 20 years\, there has been remarkable progress in the dev
 elopment of techniques for ultra-precise measurements of the penetrati
 on depth\, especially in the frequency-domain. I will briefly review t
 he major milestones where this technique has been used--from the very 
 first discovery of d-wave pairing in hole-doped cuprates [1] through d
 -wave pairing in electrondoped cuprates [2]. I will spend most of the 
 time on today's hot topic of Fe-based pnictide superconductors for whi
 ch the unconventional behavior will be demonstrated [3]. It is possibl
 e that this class of materials is one of the most complex we have ever
  encountered in the field of superconductivity due to complex multi-ba
 nd electronic structure and substantial influence of the magnetic subs
 ystem.<br>
\n<br>
\n[1] W. N. Hardy et al.\, Phys. Rev. Lett. 70\, 399
 9 (1993)<br>
\n[2] R. Prozorov et al.\, Phys. Rev. Lett. 85\, 3700 (20
 00)<br>
\n[3] R. T. Gordon et al.\, <a href="http://arxiv.org/abs/0812
 .3683">http://arxiv.org/abs/0812.3683</a>
URL:https://www.physics.wisc.edu/events/?id=1378
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