Enhancement of electronic inhomogeneities due to out-of-plane disorder in Bi2Sr2CuO6+δ superconductors observed by scanning tunneling spectroscopy
Enhancement of electronic inhomogeneities due to out-of-plane disorder in Bi2Sr2CuO6+δ superconductors observed by scanning tunneling spectroscopy
复制标题
DOI：
10.1103/physrevb.74.094503
复制
发表时间：
2006-09-01
影响因子：
3.7
通讯作者：
Uchida, S.
中科院分区：
文献类型：
--
作者：
Sugimoto, A.;Kashiwaya, S.;Uchida, S.
用低温扫描隧道显微镜和能谱研究了最佳掺杂单层超导体Bi2Sr1.6L0.4CuO6+Delta(L-Bi2201，L=La和Gd)和双层Bi2Sr2CaCu2O8+Delta(Bi2212)的纳米电子不均匀性。在Gd-Bi2201上观察到T-c以上和T-c以下的非均匀带隙结构。增加受离子半径失配控制的离面无序，导致赝能带区增强，电导谱中的相干峰受到抑制，使能隙平均变大，能隙分布变宽。在最佳掺杂的Bi2201和Bi2212中，用能隙幅度分布宽度测量的电子不均匀程度与T-c相关。
Nanoscale electronic inhomogeneity in optimally doped single-layer Bi2Sr1.6L0.4CuO6+delta, (L-Bi2201, L=La and Gd) as well as bilayer Bi2Sr2CaCu2O8+delta (Bi2212), superconductors has been investigated by the low-temperature scanning-tunneling-microscopy and spectroscopy. The inhomogeneous gap structures are observed above and below T-c on Gd-Bi2201. Increasing the out-of-plane disorder which is controlled by mismatch of the ionic radius between Sr and Ln results in the enhancement of pseudogap region with suppressed coherence peaks in the conductance spectrum, making the gap average larger and the gap distribution wider. The degree of electronic inhomogeneity measured by the distribution width of the gap amplitude is shown to have a correlation with T-c in optimally doped Bi2201 and Bi2212.