Comparison of intrinsic Josephson and SIS tunneling spectroscopy of Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+/spl delta//
Comparison of intrinsic Josephson and SIS tunneling spectroscopy of Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+/spl delta//
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Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8 /spl delta//本征约瑟夫森和SIS隧道光谱比较
DOI：
10.1109/tasc.2005.849743
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发表时间：
2005
影响因子：
1.8
通讯作者：
N. Miyakawa
中科院分区：
文献类型：
--
作者：
L. Ozyuzer;C. Kurter;J. Zasadzinski;K. E. Gray;D. Hinks;N. Miyakawa
本文报道了最佳掺杂和过掺杂Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+/spl δ //单晶的隧道光谱测量结果。采用一种新颖的点接触方法从纳米级晶体中获得超导体-绝缘体-正常金属（SIN）和SIS断结以及本征约瑟夫森结（IJJ）。在同一晶体上获得了三种结型，以比较准粒子峰和高偏置倾角/驼峰结构，这在其他表面探针如扫描隧道光谱和角分辨光电发射光谱中也发现了。然而，我们的IJJ准粒子光谱始终显示出非常尖锐的电导峰，没有更高的偏置倾角结构。与单结值相比，IJJ电导峰值电压除以堆叠中结的数量会导致显著低估/spl Delta/。三种方法的比较表明，IJJ的显著不同特征是非平衡效应的结果，而不是固有的准粒子特征。
Tunneling spectroscopy measurements are reported on optimally-doped and overdoped Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+/spl delta// single crystals. A novel point contact method is used to obtain superconductor-insulator-normal metal (SIN) and SIS break junctions as well as intrinsic Josephson junctions (IJJ) from nanoscale crystals. Three junction types are obtained on the same crystal to compare the quasiparticle peaks and higher bias dip/hump structures which have also been found in other surface probes such as scanning tunneling spectroscopy and angle-resolved photoemission spectroscopy. However, our IJJ quasiparticle spectra consistently reveal very sharp conductance peaks and no higher bias dip structures. The IJJ conductance peak voltage divided by the number of junctions in the stack consistently leads to a significant underestimate of /spl Delta/ when compared to the single junction values. The comparison of the three methods suggests that the markedly different characteristics of IJJ are a consequence of nonequilibrium effects and are not intrinsic quasiparticle features.