摘要
We investigate the dephasing rates in quasiballistic Aharonov-Bohm (AB) rings with local- and nonlocal-probe configurations by tuning the transmission through one arm of the ring. The dephasing rates are independent of the probe configuration while the transmissions through the ring paths are equal. In contrast, as AB interferometers are tuned to be strongly asymmetric, the dephasing rate of the local configuration becomes larger than that of the nonlocal configuration. We find that our observations can be qualitatively explained by voltage fluctuations from the measurement circuit, as proposed by G. Seelig, S. Pilgram, A. N. Jordan, and M. Büttiker. © 2011 American Physical Society.