The Rise of Tc: A Promising Paradigm via Interfacial Mechanism

10th International Conference on Materials and Mechanisms of Superconductivity

Chu, C.W.^1,2,3 ; Lv, B.^1 ; Deng, L.Z.^1 ; Lorenz, B.^1 ; Jawdat, B.^1 ; Gooch, M.^1 ; Shrestha, K.^1 ; Zhao, K.^1 ; Zhu, X.Y.^1 ; Xue, Y.Y.^1 ; Wei, F.Y.^1

Department of Physics, Texas Center for Superconductivity, University of Houston, Houston TX 77204-5002, United States^1

Lawrence Berkeley National Laboratory, Berkeley CA 94720, United States^2

Taiwan Comprehensive University System, Tainan, Taiwan^3

关键词: Ambient pressures;    Calorimetric investigations;    Constituent elements;    Empirical approach;    High-temperature superconductivity;    Interfacial mechanism;    Research and development;    Single-crystalline;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/449/1/012014/pdf
DOI  :  10.1088/1742-6596/449/1/012014

来源: IOP

【 摘 要 】

Following the seminal detection of superconductivity at 35 K in the first cuprate high temperature superconductor Ba-doped ternary LCO (La214) by Mueller and Bednorz in 1986, the discovery of the first liquid nitrogen superconductor quaternary YBCO (Y123) with a transition temperature Tc of 93 K by Chu, Wu, and colleagues in 1987 has ushered in the modern era of high temperature superconductivity (HTS). In the ensuing 25 years, great progress has been made in all areas of HTS research and development, from materials to physics to devices. However, the Tc remains at 134 K in quaternary HBCCO (Hg1223) at ambient pressure achieved in 1993 by Schilling et al. and at 164 K in the same compound under high pressure in the same year by Gao et al. A holistic multidisciplinary enlightened empirical approach has been proposed to search for superconductors with higher Tc, which includes the discovery of new compounds empirically and the realization of novel mechanisms proposed by theorists. Recently, we have observed nonbulk superconductivity in single crystalline rare-earth doped Ca122 samples with an onset Tc of 49 K, higher than the Tc of any known compounds formed of the constituent elements at ambient or under high pressures. Subsequent systematic structural, electrical, magnetic, and calorimetric investigations suggest that the observation may be attributed to an interface-induced Tc, thus suggesting a possible new paradigm for higher Tc. In this presentation, our results will be presented and discussed, following a brief recollection of a few events in our lab in the continuing search for higher Tc, even though a number of review articles have appeared.