Li Haoxiang, Zhou Xiaoqing, Parham Stephen, Reber Theodore J, Berger Helmuth, Arnold Gerald B, Dessau Daniel S
Department of Physics, University of Colorado at Boulder, Boulder, CO, 80309, USA.
Institute of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
Nat Commun. 2018 Jan 2;9(1):26. doi: 10.1038/s41467-017-02422-2.
Strong diffusive or incoherent electronic correlations are the signature of the strange-metal normal state of the cuprate superconductors, with these correlations considered to be undressed or removed in the superconducting state. A critical question is if these correlations are responsible for the high-temperature superconductivity. Here, utilizing a development in the analysis of angle-resolved photoemission data, we show that the strange-metal correlations don't simply disappear in the superconducting state, but are instead converted into a strongly renormalized coherent state, with stronger normal state correlations leading to stronger superconducting state renormalization. This conversion begins well above T at the onset of superconducting fluctuations and it greatly increases the number of states that can pair. Therefore, there is positive feedback--the superconductive pairing creates the conversion that in turn strengthens the pairing. Although such positive feedback should enhance a conventional pairing mechanism, it could potentially also sustain an electronic pairing mechanism.
强扩散或非相干电子关联是铜酸盐超导体奇异金属正常态的特征,这些关联在超导态中被认为是未被修饰或消除的。一个关键问题是这些关联是否是高温超导的原因。在这里,利用角分辨光电子能谱数据分析方面的进展,我们表明奇异金属关联在超导态中并非简单消失,而是相反地转变为一种强烈重整化的相干态,正常态关联越强,超导态重整化越强。这种转变在超导涨落开始时远高于临界温度(T_c)时就开始了,并且它极大地增加了能够配对的态的数量。因此,存在正反馈——超导配对产生这种转变,而这种转变反过来又加强了配对。尽管这种正反馈应该会增强传统的配对机制,但它也有可能维持一种电子配对机制。