Parity switching and decoherence by quasiparticles in single-junction transmons
Parity switching and decoherence by quasiparticles in single-junction transmons
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DOI：
10.1103/physrevb.89.094522
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发表时间：
2014-03-31
影响因子：
3.7
通讯作者：
Catelani, G.
中科院分区：
文献类型：
--
作者：
Catelani, G.
跨声子超导量子比特被认为是实现量子信息处理的一种很有前途的方法，并且已经在二维和三维结构中获得了10(6)阶的高质量因子。这些高质量的因素使得对退相干机制的详细研究成为可能。本征退相干过程源于量子比特自由度和穿过约瑟夫森结的准粒子之间的耦合。在跨声子中，单个准粒子的隧穿与宇称的变化有关。在这里，我们提出了单结跨子奇偶转换速率的理论，并将其与最近的测量结果进行了比较。我们还表明奇偶转换在限制相干时间方面可以起到重要作用。
The transmon superconducting qubit is being intensely investigated as a promising approach for the physical implementation of quantum information processing, and high-quality factors of order 10(6) have been achieved both in two- and three-dimensional architectures. These high-quality factors enable detailed investigations of decoherence mechanisms. An intrinsic decoherence process originates from the coupling between the qubit degree of freedom and the quasiparticles that tunnel across Josephson junctions. In a transmon, tunneling of a single quasiparticle is associated with a change in parity. Here we present the theory of the parity-switching rates in single-junction transmons and compare it with recent measurements. We also show that parity switching can have an important role in limiting the coherence time.