Abstract
A spin-echo-type technique is applied to an artificial two-level system that utilizes a charge degree of freedom in a small superconducting electrode. Gate-voltage pulses are used to produce the necessary pulse sequence in order to eliminate the inhomogeneity effect in the time-ensemble measurement and to obtain refocused echo signals. Comparison of the decay time of the observed echo signal with an estimated decoherence time suggests that low-frequency energy-level fluctuations due to the charge noise dominate the dephasing in the system.
- Received 5 September 2001
DOI:https://doi.org/10.1103/PhysRevLett.88.047901
©2002 American Physical Society