Dresden 2003 – wissenschaftliches Programm
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SYQD: Quantum decoherence in solid state physics
SYQD 1: Quantum Decoherence in Solid State Physics I
SYQD 1.3: Hauptvortrag
Dienstag, 25. März 2003, 15:00–15:30, HSZ/01
High Field Measurements of Electron Dephasing Time: Switching of Magnetic Impurities — •Raj Mohanty1 and Richard Webb2 — 1Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA — 2Department of Physics, University of Maryland, College Park, MD 20742, USA
We report low-temperature measurements of electron decoherence time in a series of pure gold wires, 18 nm thick and 30 nm wide. At fields up to 15 tesla, large enough to polarize any concentration of magnetic impurity spins, conductance fluctuation measurements show a weak temperature dependence of decoherence time, both in the correlation field for interference and in the root-mean-square value of the fluctuations. Combined with previous low-field weak localization measurements on samples from similar material, our experiment suggests that the ubiquitous saturation of decoherence time in these samples is not due to any mechanism based on magnetic impurity spins.