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CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1730
DTSTART:20100304T160000Z
DURATION:PT1H0M0S
DTSTAMP:20260412T064224Z
LAST-MODIFIED:20100210T184511Z
LOCATION:5310 Chamberlin
SUMMARY:Fermi Surface investigation across the quantum critical point 
 in CeIrIn5 and CeCoIn5 via de Haas van Alphen measurements\, R. G. Her
 b Condensed Matter Seminar\, Cidgem Capan\, UC-Irvine
DESCRIPTION:A quantum critical point (QCP) is a continuous ground stat
 e transformation at T=0\, tuned by an external parameter such as press
 ure\, chemical doping or magnetic field. The critical behavior associa
 ted with this T=0 thermodynamic singularity may be the common feature 
 underlying the similar phase diagrams found in a wide variety of stron
 gly correlated systems\, including cuprates\, ruthenates\, heavy fermi
 ons and iron pnictides. Among these systems\, the heavy fermion compou
 nds\, rare-earth materials exhibiting large effective masses\, have pl
 ayed a particularly important role for investigating the evolution of 
 the Fermi surface across a QCP. In these materials it is the competing
  tendency of conduction electrons to screen or to mediate a magnetic c
 oupling among the f-electrons that ultimately leads to a QCP. The impo
 rtant and still open question regarding the underlying mechanism of th
 e QCP is whether the Fermi surface volume changes abruptly at the onse
 t of magnetic ordering. Following a broad introduction\, I will focus 
 on two heavy fermion superconductors: CeMIn5 with M=Co\,Ir. These rece
 ntly discovered compounds illustrate well the shortcomings of our curr
 ent understanding of quantum criticality: despite the thermodynamic an
 d transport evidence for non-Fermi Liquid behavior in these systems\, 
 their Fermi surface\, as investigated by de Haas van Alphen effect\, d
 oes not show a drastic change across the putative QCP. The implication
 s and possible scenarios will be discussed.
URL:https://www.physics.wisc.edu/events/?id=1730
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