Center for Correlated Electron Systems

Seminar

Road to high Tc superconductivity: A new route

July 20, 2020l Hit 415
Date : December 19, 2019 16:00 ~ 17:30
Speaker : Prof. Shin-ichi Uchida (University of Tokyo)
Location : Bldg. 19, Rm. 210

A high-Tc cuprate (Tc = 73 K) with a chemical formula Ba2CuO4-y (BCO) has been synthesized at high pressure (~ 18 GPa). In this new cuprate, (i) the apical-O is located very close to the plane [1], (ii) the hole doping level is very high well beyond the Tc-dome of the so far known cuprates [1], and (iii) ~ 40% of the in-plane O sites are vacant (nominal composition Ba2CuO3.2). These features, in particular (iii), indicate that BCO is a new type of high-Tc cuprates. It is highly likely that its Sr counterpart, Sr2CuO4-y, with Tcmax = 98 K [2] belongs to the same class. BCO is, thus, a member of a different branch of the high-Tc materials toward higher Tc superconductivity [3].

 

This work has been performed in collaboration with C.Q Jin, W.M. Li, L.P. Cao, J.F. Zhao R.Z. Yu, J. Zhang, Y. Liu, Q.Q. Liu, X.C. Wang, Y.W. Long (IOP-CAS, Beijing), Z. Hu (MPI, Dreseden), Q.Z. Huang, H. Wu (NIST, Gaithersburg), H.J. Lin, C.T. Chen (NSRRC, Hsinchu), Z. Li (Nanjing University of Science and Technology), Z.Z. Gong, Z. Guguchia, Y.J. Uemura (Columbia University), J.S. Kim, G. Stewart (University of Florida).

 

[1] W.M. Li et al., Proc. Nat. Acad. Sci. 116, 12156 (2019).

[2] W.B. Gao et al., Phys. Rev. B 80, 094523 (2009).

[3] D.J. Scalapino, Proc. Nat. Acad. Sci. 116, 12129 [Commentary] (2019).

 

 

Host: Prof. Changyoung Kim