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UID:UW-Physics-Event-1553
DTSTART:20090611T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260422T164448Z
LAST-MODIFIED:20090604T131030Z
LOCATION:5310 Chamberlin
SUMMARY:Intriguing Magneto-transport Behavior in Nanostructured NbN Su
 perconductors and in Nanowires of the NbSe<sub>3</sub> Charge Density 
 Wave System\, R. G. Herb Condensed Matter Seminar\, Umesh Patel\, Argo
 nne National Lab
DESCRIPTION:Superconducting nanostructures are highly desirable in fut
 ure nanodevices and also provide a unique platform to search for new s
 uperconducting phenomena in confined geometries. I will describe a nov
 el synthesis approach used to transform nanostructures of the charge d
 ensity wave material NbSe<sub>3</sub> into superconducting NbN and NbS
 e<sub>2</sub> nanowires and nanoribbons. Subsequent four-probe magneto
 -transport studies on individual superconducting NbN nanostructures re
 veal an intriguing oscillatory behavior in the magnetoresistance and c
 ritical current. These oscillations can be understood within the frame
 work of quantized magnetic flux cutting through phase coherent loops o
 f superconducting grains composing the nanostructure. The size of the 
 phase coherent grain loop sets the relevant parameter for the observed
  oscillation periods. Although the transverse dimensions of our NbN na
 nostructures are much larger than the superconducting coherence length
 \, the voltage-current characteristics of these granular NbN nanostruc
 tures at low temperatures are remarkably reminiscent of those observed
  in one-dimensional superconductors where dissipation is associated wi
 th quantum phase slips (QPS). Our results highlight the complexity of 
 probing QPS in superconducting nanostructures. In addition\, I will re
 port on transport studies of NbSe<sub>3</sub> nanostructures where we 
 observed a magneto-resistance peak at low magnetic fields related to c
 onfinement of electron trajectories at low temperatures. 
URL:https://www.physics.wisc.edu/events/?id=1553
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