We report the observation of quantum jumps between macroscopic quantum states in a superconducting phase qubit coupled to the two-level systems in the Josephson tunnel junction, and all key features of quantum jumps are confirmed in the experiments. Moreover, quantum jumps can be used to calibrate such two-level systems, which are believed to be one of the main decoherence sources in Josephson devices.
@article{arxiv.0807.0766,
title = {Quantum Jumps between Macroscopic Quantum States of a Superconducting Qubit Coupled to a Microscopic Two-Level System},
author = {Yang Yu and Shi-Liang Zhu and Guozhu Sun and Xueda Wen and Ning Dong and Jian Chen and Peiheng Wu and Siyuan Han},
journal= {arXiv preprint arXiv:0807.0766},
year = {2009}
}