Novel Electronic State and Superconductivity in the Electron-Doped High-Tc T’-Superconductors
Department of Engineering and Applied Sciences, Sophia University, Tokyo 102-8554, Japan
Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
Author to whom correspondence should be addressed.
Received: 28 April 2017 / Revised: 27 June 2017 / Accepted: 27 June 2017 / Published: 4 July 2017
In this review article, we show our recent results relating to the undoped (Ce-free) superconductivity in the electron-doped high-
cuprates with the so-called T’ structure. For an introduction, we briefly mention the characteristics of the electron-doped T’-cuprates, including the reduction annealing, conventional phase diagram and undoped superconductivity. Then, our transport and magnetic results and results relating to the superconducting pairing symmetry of the undoped and underdoped T’-cuprates are shown. Collaborating spectroscopic and nuclear magnetic resonance results are also shown briefly. It has been found that, through the reduction annealing, a strongly localized state of carriers accompanied by an antiferromagnetic pseudogap in the as-grown samples changes to a metallic and superconducting state with a short-range magnetic order in the reduced superconducting samples. The formation of the short-range magnetic order due to a very small amount of excess oxygen in the reduced superconducting samples suggests that the T’-cuprates exhibiting the undoped superconductivity in the parent compounds are regarded as strongly correlated electron systems, as well as the hole-doped high-
cuprates. We show our proposed electronic structure model to understand the undoped superconductivity. Finally, unsolved future issues of the T’-cuprates are discussed.
This is an open access article distributed under the Creative Commons Attribution License
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
Share & Cite This Article
MDPI and ACS Style
Adachi, T.; Kawamata, T.; Koike, Y. Novel Electronic State and Superconductivity in the Electron-Doped High-Tc T’-Superconductors. Condens. Matter 2017, 2, 23.
Adachi T, Kawamata T, Koike Y. Novel Electronic State and Superconductivity in the Electron-Doped High-Tc T’-Superconductors. Condensed Matter. 2017; 2(3):23.
Adachi, Tadashi; Kawamata, Takayuki; Koike, Yoji. 2017. "Novel Electronic State and Superconductivity in the Electron-Doped High-Tc T’-Superconductors." Condens. Matter 2, no. 3: 23.
Show more citation formats
Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
[Return to top]
Multiple requests from the same IP address are counted as one view.