Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 23: Spin controlled transport II
HL 23.1: Vortrag
Dienstag, 27. März 2007, 14:00–14:15, H14
Electrical detection of donor Rabi flops — •Hans Huebl1, Andre Stegner1, Felix Hoehne1, Christoph Boehme2, Klaus Lips3, Martin Stutzmann1, and Martin Brandt1 — 1Walter Schottky Institut, Garching, Germany — 2University of Utah, Salt Lake City, USA — 3Hahn Meitner Institut, Berlin,Germany
Due to its potential compatibility with existing microelectronics, the proposal for a silicon based quantum computer by Kane is being pursued intensively. In this concept, the nuclear spins of single 31P donors serve as qubits. Exchange coupling between donor-bound electrons, whose spins experience hyperfine interaction with their nuclei enables two and more qubit operations. An experimentally unsolved key issue is the readout of the 31P quantum state. We demonstrate the measurement of the spin state of 31P donor electrons in silicon and the observation of Rabi flops by purely electric means, carrying out pulsed electrically detected magnetic resonance experiments (pEDMR). Resonant microwave pulses are used to induce coherent manipulation of an ensemble of 31P electron spins by electron spin resonance. The resulting change of spin-dependent charge-carrier recombination between the 31P donor and paramagnetic localized states at the silicon surface is then detected by a transient photoconductivity measurement after the coherent excitation is turned off. The electron spin information is shown to be coupled through the hyperfine interaction to the phosphorus nucleus, suggesting that recombination-based readout of nuclear spins is feasible.