Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 13: Spin controlled transport I
HL 13.7: Vortrag
Dienstag, 28. März 2006, 12:30–12:45, BEY 118
Detection of few phosphorus donors in silicon — •H. Huebl1, D. R. McCamey2,3, M. Lunz1, W. Hutchison2,4, J. C. McCallum2,5, A. R. Hamilton3, R. G. Clark2,3, and M. S. Brandt1 — 1Walter Schottky Institut, Germany — 2Australian Research Council Centre of Excellence for Quantum Computer Technology — 3School of Physics, The University of New South Wales, Sydney, Australia — 4School of Physical, Environmental and Mathematical, University College, The University of New South Wales ADFA,Canberra, Australia — 5School of Physics, University of Melbourne, Australia
One of the concepts for scalable solid-state based quantum computing is Kane’s proposal based on phosphorus donors in silicon. To estimate the sensitivity which is reached with magnetic resonance techniques in the detection of donor spins, we have measured electrically detected magnetic resonance (EDMR) on devices containing a few phosphorus donors only.
In the devices studied phosphorus with a concentration of 2× 1017 cm−3 is implanted at 15 keV into intrinsic silicon in an area of 100×100 nm2 defined by electron beam lithography. The leads contacting this island are also obtained by implantation with P, however to a concentration above the Mott transition which does not lead to an EDMR signal.
At 5 K and under illumination, a resonant change of the conductivity Δσ/σ≈10−5 is observed for an island containing 85± 10 atoms. From the signal-to-noise ratio, a sensitivity of about 600 P/√number of field scans can be deduced for the samples investigated so far. This experiments demonstrate the possibilities for investigating the properties of a few of donors and indicates that single spin resolution should be achievable.