Damping Factor of the Riedel Peak in Bridge-Type Josephson Junctions
Damping Factor of the Riedel Peak in Bridge-Type Josephson Junctions
复制标题
桥式约瑟夫森结 Riedel 峰的阻尼系数
DOI：
10.1143/jpsj.52.617
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发表时间：
1983
影响因子：
1.7
通讯作者：
N. Mikoshiba
中科院分区：
文献类型：
--
作者：
S. Morita;S. Imai;I. Fukushi;S. Takaki;Y. Takeuti;N. Mikoshiba
用亚毫米波激光测量了桥式点接触约瑟夫森结中基本Shapiro阶跃（n =1）的最大高度与频率的关系，研究了约瑟夫森电流的Riedel峰，其中Δ 0为能隙的真实的部分，能量范围在\（\hbar\omega{\sim} 4\varDelta_{0}\）附近.能隙的虚部Δ 2是由观测到的里德尔奇点的圆整估计出来的。结果得到阻尼因子\（\delta{=}\varDelta_{2}/\varDelta_{0}{\gtrsim}0.05\）。δ 0.05的值似乎是桥型结固有的最低值。还发现在热效应较强的结中δ值较大。
The Riedel peak in the Josephson current in bridge-type point-contact Josephson junctions has been studied by measuring the frequency dependence of the maximum height of the fundamental ( n =1) Shapiro-step in the energy range near \(\hbar\omega{\sim}4\varDelta_{0}\) with a submillimeter-wave laser, where Δ 0 is the real part of the energy gap. The imaginary part of the energy gap, Δ 2 , has been estimated from the observed rounding of the Riedel singularity. As a result, the damping factor \(\delta{=}\varDelta_{2}/\varDelta_{0}{\gtrsim}0.05\) has been obtained. The value of δ∼0.05 seems to be the lowest value which is intrinsic to bridge-type junctions. It has been also found that the value of δ is large in the junctions which show strong heating effects.