An intrinsic bond-centered electronic glass with unidirectional domains in underdoped cuprates
An intrinsic bond-centered electronic glass with unidirectional domains in underdoped cuprates
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DOI：
10.1126/science.1138584
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发表时间：
2007-03-09
期刊：
影响因子：
56.9
通讯作者：
Davis, J. C.
中科院分区：
文献类型：
--
作者：
Kohsaka, Y.;Taylor, C.;Davis, J. C.
从铜酸盐的CuO 2平面去除电子改变了电子相关性，足以产生高温超导性。与这些变化相关联的是从绝缘体的高能量状态到低能量的谱重转移。理论上，这些应该是可检测的，因为电子注入和提取的隧穿速率之间的不平衡-隧穿不对称性。我们引入原子分辨率的隧道不对称成像，发现几乎相同的现象，在两个轻度空穴掺杂的铜酸盐：Ca1.88Na0.12CuO2Cl2和Bi2Sr2Dy0.2Ca0.8Cu2O8+ δ。隧穿不对称性的强烈空间变化主要发生在平面氧位点;它们的空间排列形成了以Cu-O-Cu键为中心的电子图案，没有长程有序，但具有4a（0）宽的单向电子畴分散在整个区域（a（0）：Cu-O-Cu距离）。新兴的图片，然后在本征电子玻璃内的部分空穴局域化的演变，在更高的空穴密度，到完全离域和最高温度的超导性。
Removing electrons from the CuO2 plane of cuprates alters the electronic correlations sufficiently to produce high-temperature superconductivity. Associated with these changes are spectral-weight transfers from the high-energy states of the insulator to low energies. In theory, these should be detectable as an imbalance between the tunneling rate for electron injection and extraction - a tunneling asymmetry. We introduce atomic-resolution tunneling-asymmetry imaging, finding virtually identical phenomena in two lightly hole-doped cuprates: Ca1.88Na0.12CuO2Cl2 and Bi2Sr2Dy0.2Ca0.8Cu2O8+delta. Intense spatial variations in tunneling asymmetry occur primarily at the planar oxygen sites; their spatial arrangement forms a Cu-O-Cu bond-centered electronic pattern without long-range order but with 4a(0)-wide unidirectional electronic domains dispersed throughout (a(0): the Cu-O-Cu distance). The emerging picture is then of a partial hole localization within an intrinsic electronic glass evolving, at higher hole densities, into complete delocalization and highest-temperature superconductivity.