Protected Josephson Rhombus chains.
Protected Josephson Rhombus chains.
复制标题
受保护的约瑟夫森菱形链条。
DOI：
10.1103/physrevlett.112.167001
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发表时间：
2013
影响因子：
8.6
通讯作者：
M. Gershenson
中科院分区：
文献类型：
--
作者：
M. Bell;J. Paramanandam;L. Ioffe;M. Gershenson
我们研究了一个包含两个基本元件(菱形)的极小保护约瑟夫森电路中的低能激发，该基本元件以约瑟夫森能量的π周期为特征。这些元件采用了新颖的设计，降低了它们对偏置电荷波动的敏感性。我们观察到，在保护态下，该量子电路第一激发态的寿命T1增加到70 μS，比无保护态时的寿命提高了100倍。该量子比特的品质因数ω01T1超过106.我们的结果与理论预期是一致的；它们证明了用现有技术制造的菱形基量子比特中对称保护的可行性。
We have studied the low-energy excitations in a minimalistic protected Josephson circuit which contains two basic elements (rhombi) characterized by the π periodicity of the Josephson energy. Novel design of these elements, which reduces their sensitivity to the offset charge fluctuations, has been employed. We have observed that the lifetime T1 of the first excited state of this quantum circuit in the protected regime is increased up to 70 μs, a factor of ∼100 longer than that in the unprotected state. The quality factor ω01T1 of this qubit exceeds 106. Our results are in agreement with theoretical expectations; they demonstrate the feasibility of symmetry protection in the rhombus-based qubits fabricated with existing technology.