2008/03/05 by Josef-Stefan Wenzler, Pritiraj Mohanty
Engineering · Physics and Astronomy · #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #Terahertz technology and applications #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.77.121102
5 pages, two figures, one table, two-column format.To be published in Phys. Rev. B (rapid comm.). Related papers can be found at http://nano.bu.edu/
arxiv created 2008/03/05 · openalex publication_date 2008/03/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report measurements of Aharonov-Bohm oscillations in normal metal rings in the presence of high-frequency electromagnetic fields. The power dependence of the decoherence time scale \ensuremathτ_\ensuremathφ(P) agrees well with the anticipated power law \ensuremathτ_\ensuremathφ\ensuremath∝P^\ensuremath-1∕5 when the field-induced decoherence rate \ensuremathτac^\ensuremath-1 is large compared to the intrinsic decoherence rate \ensuremathτo^\ensuremath-1, measured in the absence of external fields. As theoretically expected, we observe a decline in field-induced decoherence when \ensuremathτac^\ensuremath-1\ensuremath\leqslant\ensuremathτo^\ensuremath-1. The frequency dependence of \ensuremathτ_\ensuremathφ shows a minimum in the oscillation amplitude at a characteristic frequency \ensuremathωac\ensuremath≃1∕\ensuremathτo, where \ensuremathτo is evaluated from the oscillation amplitude using the standard mesoscopic theory. Both the suppression in the oscillation amplitude and the concomitant change in conductivity allow a direct measurement of the intrinsic decoherence time scale.