Undoped cuprate superconductors - band superconductors or oxygen-doped Mott-Hubbard superconductors?

被引：13

作者：

Naito, M. ^{[1
]}

Matsumoto, O. ^{[1
]}

Utsuki, A. ^{[1
]}

Tsukada, A. ^{[2
]}

Yamamoto, H. ^{[3
]}

Manabe, T. ^{[4
]}

机构：

[1] Tokyo Univ Agr & Technol, Dept Appl Phys, Naka Cho 2-24-16, Koganei, Tokyo 1848588, Japan

[2] Stanford Univ, Geballe Lab Adv Mat, Stanford, CA 94305 USA

[3] NTT Corp, NTT Sci & Core Technol Lab Grp, Atsugi, Kanagawa 2430198, Japan

[4] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058565, Japan

来源：

INTERNATIONAL SYMPOSIUM ON LATTICE EFFECTS IN CUPRATE HIGH TEMPERATURE SUPERCONDUCTORS (LEHTSC2007) | 2008年 / 108卷

基金：

日本学术振兴会;

关键词：

D O I：

10.1088/1742-6596/108/1/012037

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Undoped cuprates have long been considered to be antiferromagnetic Mott insulators (charge-transfer insulators). In this article we report that one group of cuprates, namely RE2CuO4 with the Nd2CuO4 (T') structure, become superconducting without doping. Our discovery was achieved by metal-organic decomposition, an inexpensive and easy-to-implement thin-film process. The highest T-c of undoped T'-RE2CuO4 is over 30 K, substantially higher than their "electron-doped" analogs. Remarkably, Gd2CuO4, even the derivatives of which have not shown superconductivity so far, gets superconducting with T-c(onset) as high as 20 K. Our discovery contradicts with the past results supporting undoped cuprates to be generally insulating. The clue to understanding the sharp contrast between the past and our results is impurity oxygen (O-ap) at the apical site. The implication of our discovery is briefly discussed.

引用

页数：6

共 17 条

[1] EXTENDED SUPERCONDUCTING CONCENTRATION RANGE OBSERVED IN PR2-XCEXCUO4-DELTA [J].