Electron Decoherence by a Single Spin
نویسنده
چکیده
Recently it has been suggested that the ubiquitous saturation of electron dephasing time at low temperatures could be due to an extremely small number of magnetic impurities—even as small as a single magnetic spin. However, extensive data from a series of recent experiments at both low and high magnetic fields clearly indicate the contrary. At high magnetic fields, the spins, irrespective of their number or concentration, freeze along the field, and the electron dephasing time is determined only by mechanisms that do not involve magnetic impurities. This dephasing time measured via conductance fluctuations still saturates at low temperatures, unequivocally suggesting that the saturation is not due to a mechanism that involves magnetic impurities at any level.
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