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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1173
DTSTART:20080501T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260422T215753Z
LAST-MODIFIED:20080425T131835Z
LOCATION:5310 Chamberlin
SUMMARY:Magnetic 1/f noise from the semiconductor/oxide interface and 
 spin-dependent scattering in silicon transistors\, R. G. Herb Condense
 d Matter Seminar\, Rogerio de Sousa\, University of Victoria
DESCRIPTION:In the first part of the talk I will discuss a mechanism o
 f magnetic noise based on spin-flips of paramagnetic dangling-bonds at
  the semiconductor/oxide interface. The spin-flips are caused by the c
 ross-relaxation of dangling-bond spins with the tunnelling-two-level-s
 ystems of the amorphous interface\, leading to magnetic 1/f noise even
  at zero magnetic field. I will compare and fit this model to a recent
  electron spin resonance experiment in nuclear-spin free silicon\, and
  show that the same amount of interface noise detected by spin resonan
 ce may explain the intrinsic flux noise of the best superconducting qu
 antum interference devices (SQUIDs).<br>
\n<br>
\nIn the second part I
  will describe a theory of spin-dependent scattering in the two-dimens
 ional electron gas of silicon transistors. The scattering of conductio
 n electrons off neutral donor impurities depends sensitively on the re
 lative orientation of their spin states\, and the six-fold degeneracy 
 of the silicon conduction band leads to a strongly oscillatory couplin
 g of conduction electrons to donors placed at varying depths in the tr
 ansistor channel.  This coupling can be gate controlled\, enabling opt
 imization for single donor spin readout and spatially resolved charact
 erization of the conduction electron spin polarization that does not r
 ely on weak spin-orbit coupling effects or interface scattering.
URL:https://www.physics.wisc.edu/events/?id=1173
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