Johnson Philip R, Parsons William T, Strauch Frederick W, Anderson J R, Dragt Alex J, Lobb C J, Wellstood F C
Department of Physics, University of Maryland, College Park, MD 20850, USA.
Phys Rev Lett. 2005 May 13;94(18):187004. doi: 10.1103/PhysRevLett.94.187004.
Prototype Josephson-junction based qubit coherence times are too short for quantum computing. Recent experiments probing superconducting phase qubits have revealed previously unseen fine splittings in the transition energy spectra. These splittings have been attributed to new microscopic degrees of freedom (microresonators), a previously unknown source of decoherence. We show that macroscopic resonant tunneling in the extremely asymmetric double-well potential of the phase qubit can have observational consequences that are strikingly similar to the observed data.
基于约瑟夫森结的原型量子比特的相干时间对于量子计算来说太短了。最近对超导相位量子比特进行探测的实验揭示了跃迁能谱中以前未见过的精细分裂。这些分裂被归因于新的微观自由度（微谐振器），这是一种以前未知的退相干源。我们表明，相位量子比特的极不对称双阱势中的宏观共振隧穿可能会产生与观测数据惊人相似的观测结果。
