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PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1876
DTSTART:20100806T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260422T092138Z
LAST-MODIFIED:20100804T160810Z
LOCATION:5310 Chamberlin
SUMMARY:Silicon enhancement mode nanostructures for few electron spin 
 devices\, R. G. Herb Condensed Matter Seminar\, Malcolm Carroll\, Sand
 ia National Laboratory
DESCRIPTION:Promising coherent control of single electron spins in mod
 ulation doped\, depletion mode\, GaAs quantum dots has been demonstrat
 ed [1] with spin decoherence times order of 30 ms with Hahn echo [2]. 
  Spin decoherence times orders of magnitude longer\, > 0.6 seconds\, h
 ave been measured in ensemble spin measurements in silicon but have no
 t yet been realized in single spin silicon nanostructures although num
 erous groups are showing rapid progress towards this goal.  Achieving 
 single electron spin control with long decoherence times will likely r
 equire low charge and magnetic disordered silicon devices.  This has r
 epresented a long standing challenge to the community resulting in the
  examination of numerous materials\, device design and process integra
 tion approaches. This talk will describe a silicon metal oxide semicon
 ductor (MOS)\, open-lateral gated design that produces a confined pote
 ntial for electrons at the SiO2/Si interface that allows sufficient tu
 nability to both form well behaved double quantum dots (DQD) and overc
 ome some electrostatic non-uniformity in the nanostructure.  This stru
 cture further provides the ability to implant the quantum dot structur
 es with impurities (Sb)\, which provides an alternate path to obtainin
 g single electron potentials that can couple and be manipulated by the
  DQD structure.  Electrical transport of both low disorder MOS quantum
  dots and impurity implant induced resonances will be presented.  Mode
 ling of the electrostatics and the excited state spectroscopy of these
  systems is used to begin to clarify the source of the single electron
  transport.  The effects of processing induced defects and background 
 impurities in the metal oxide semiconductor (MOS) system on electrosta
 tic and magnetic effects on the qubit will also be discussed if time p
 ermits. <br>
\n <br>
\nWe wish to acknowledge the research funding sup
 port provided by the laboratory directed research and development (LDR
 D) program at Sandia National Laboratories.  Sandia National Labs is a
  multi-program laboratory operated by Sandia Corporation\, a Lockheed 
 Martin Company\, for the United States Department of Energy's National
  Nuclear Security Administration under contract DE-AC04-94AL85000. <br
 >
\n <br>
\n[1] J. Petta et al.\, Science 309\, 2180 (2005)<br>
\n[2] 
 H. Bluhm et al.\, arXiv: 1005.2995 (2010)<br>
\n 
URL:https://www.physics.wisc.edu/events/?id=1876
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