Nakamura, Y. and Pashkin, Yuri and Yamamoto, T. and Tsai, Jaw-Shen (2002) Charge Echo in a Cooper-Pair Box. Physical review letters, 88 (4): 047901. ISSN 0031-9007
Full text not available from this repository.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 1 / f charge noise dominate the dephasing in the system.