We irradiated an rf-SQUID qubit with large-amplitude and high frequency electromagnetic field. Population transitions between macroscopic distinctive quantum states due to Landau-Zener transitions at energy-level avoided crossings were observed. The qubit population on the excited states as a function of flux detuning and microwave power exhibits interference patterns. Some novel features are found in the interference and a model based on rate equations can well address the features.
@article{arxiv.0912.0995,
title = {Quantum interference induced by multiple Landau-Zener transitions in a strongly driven rf-SQUID qubit},
author = {Yiwen Wang and Shanhua Cong and Xueda Wen and Cheng Pan and Guozhu Sun and Jian Chen and Lin Kang and Weiwei Xu and Yang Yu and Peiheng Wu},
journal= {arXiv preprint arXiv:0912.0995},
year = {2017}
}