Pair Breaking in s-Wave Superconductors by Two-Channel Kondo Impurities
Pair Breaking in s-Wave Superconductors by Two-Channel Kondo Impurities
复制标题
DOI：
10.1007/978-94-010-0427-5_33
复制
发表时间：
2001
影响因子：
3.7
通讯作者：
G. Sellier;S. Kirchner;Johann Kroha
中科院分区：
文献类型：
--
作者：
G. Sellier;S. Kirchner;Johann Kroha
对介观系统的几个实验表明，在低温T [1]下，电子退相速率明显为1/τφ。这种退相饱和的起源是凝聚态物理学的基本兴趣，以及涉及量子相位相干的纳米级器件的设计相关。τφ的饱和值对材料类型和样品制备技术的强烈依赖性暗示了一种非电子液体固有的失相机制。有人提出，晶体结构中的动力学结构缺陷，如二能级系统（TLS），耦合到电子系统，可以导致在低T的退相。为了解释实验，这需要能级分裂δ，P（δ）δ 1/δ [2]的分布，或者相当大比例的TLS，其中δ5消失，产生双通道近藤（2CK）效应[3]。
Several experiments on mesoscopic systems indicate an apparently non-vanishing electron dephasing rate 1/τφ at low temperaturesT[1]. The origin of this dephasing saturation is of fundamental interest in condensed matter physics as well as relevant for the design of nanoscale devices involving quantum phase coherence. The strong dependence of the saturation value of τφ on the type of material and on the sample preparation technique hints at a dephasing mechanism which is not intrinsic to the electron liquid. It has been proposed that dynamical structural defects in the crystal structure like two-level systems (TLS), coupled to the electron system, could cause dephasing at lowT. In order to account for the experiments this requires either a distribution of level splittings δ ,P(δ) ∝ 1/δ [2], or a sizable fraction of TLS with vanishing δ5 which produce a two-channel Kondo (2CK) effect [3].