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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1531
DTSTART:20090519T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260310T212131Z
LAST-MODIFIED:20090519T133439Z
LOCATION:5310 Chamberlin
SUMMARY:Electrical Control of a Hydrogenic Donor's Spin in Semiconduct
 or Nanostructures\, R. G. Herb Condensed Matter Seminar\, Amrit De\, U
 niversity of Iowa
DESCRIPTION:A quantum-information processing scheme based on electric-
 field dependent manipulation of spin-information for a shallow hydroge
 nic impurity is investigated. Calculations for electrical g tensor mod
 ulation for a single Silicon donor embedded in a GaAs-substrate is don
 e by extending the effective mass treatment of shallow donors to the 8
 -band k.p model. The electric-field(E) quenches the donor electron's o
 rbital angular momentum by altering quantum-confinement which modulate
 s the g tensor. The calculated g-factors are highly nonlinear function
 s of the applied electric and magnetic fields and is unlike that seen 
 in quantum dots. This is attributed to the weaker nature of the confin
 ement potential for a shallow donor atom. The donor electron's spin-dy
 namics\, for the spin-split-1S level\, was calculated exactly by using
  time evolution operators. It is seen that as a consequence of the non
 linear nature of g(E)\, spin-flip transitions can be made resonantly a
 t subharmonics of the Larmor frequency. Possibilities of using 2D and 
 1D quantum confinement to obtain more rapid Rabi oscillations is being
  investigated. I will also briefly discuss some of our work on nanowir
 es\, which includes g-factor calculations for nanowhisker-quantum-dots
 \, comparison with experiment and related pseudopotential band structu
 re calculations.
URL:https://www.physics.wisc.edu/events/?id=1531
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