Observation of small Fermi pockets protected by clean CuO2 sheets of a high-Tc superconductor

DOI: 10.1126/science.aay7311

Authors: So Kunisada (University of Tokyo) , Shunsuke Isono (Tokyo University of Science) , Yoshimitsu Kohama (University of Tokyo) , Shiro Sakai (RIKEN Center for Emergent Matter Science (CEMS)) , Cédric Bareille (University of Tokyo) , Shunsuke Sakuragi (University of Tokyo) , Ryo Noguchi (University of Tokyo) , Kifu Kurokawa (University of Tokyo) , Kenta Kuroda (University of Tokyo) , Yukiaki Ishida (University of Tokyo) , Shintaro Adachi (MANA, National Institute for Materials Science, Japan) , Ryotaro Sekine (Tokyo University of Science) , Timur K. Kim (Diamond Light Source) , Cephise Cacho (Diamond Light Source) , Shik Shin (University of Tokyo) , Takami Tohyama (Tokyo University of Science) , Kazuyasu Tokiwa (Tokyo University of Science) , Takeshi Kondo (University of Tokyo)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Science , VOL 369 , PAGES 833-838

State: Published (Approved)
Published: August 2020
Diamond Proposal Number(s): 20445 , 20446

Abstract: In cuprate superconductors with high critical transition temperature (Tc), light hole-doping to the parent compound, which is an antiferromagnetic Mott insulator, has been predicted to lead to the formation of small Fermi pockets. These pockets, however, have not been observed. Here, we investigate the electronic structure of the five-layered Ba2Ca4Cu5O10(F,O)2, which has inner copper oxide (CuO2) planes with extremely low disorder, and find small Fermi pockets centered at (π/2, π/2) of the Brillouin zone by angle-resolved photoemission spectroscopy and quantum oscillation measurements. The d-wave superconducting gap opens along the pocket, revealing the coexistence between superconductivity and antiferromagnetic ordering in the same CuO2 sheet. These data further indicate that superconductivity can occur without contribution from the antinodal region around (π, 0), which is shared by other competing excitations.

Diamond Keywords: Antiferromagnetism

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Added On: 17/08/2020 14:31

Discipline Tags:

Superconductors Quantum Materials Hard condensed matter - electronic properties Physics Magnetism Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)