Rapid change of superconductivity and electron-phonon coupling through critical doping in Bi-2212

Y He; M Hashimoto; D Song; S-D Chen; J He; I M Vishik; B Moritz; D-H Lee; N Nagaosa; J Zaanen; T P Devereaux; Y Yoshida; H Eisaki; D H Lu; Z-X Shen

doi:10.1126/science.aar3394

Rapid change of superconductivity and electron-phonon coupling through critical doping in Bi-2212

Science. 2018 Oct 5;362(6410):62-65. doi: 10.1126/science.aar3394.

Authors

Y He^{1

2}, M Hashimoto³, D Song⁴, S-D Chen^{1

2}, J He^{1

2}, I M Vishik¹, B Moritz^{1

2}, D-H Lee⁵, N Nagaosa⁶, J Zaanen⁷, T P Devereaux^{1

2}, Y Yoshida⁴, H Eisaki⁴, D H Lu³, Z-X Shen^{8

2}

Affiliations

¹ Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA.
² SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.
³ Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.
⁴ National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan.
⁵ Department of Physics, University of California, Berkeley, CA 94720, USA.
⁶ Quantum-Phase Electronics Center, Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
⁷ Instituut-Lorentz for Theoretical Physics, Leiden University, Leiden, Netherlands.
⁸ Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA. zxshen@stanford.edu.

PMID: 30287656
DOI: 10.1126/science.aar3394

Abstract

Electron-boson coupling plays a key role in superconductivity for many systems. However, in copper-based high-critical temperature (T _c) superconductors, its relation to superconductivity remains controversial despite strong spectroscopic fingerprints. In this study, we used angle-resolved photoemission spectroscopy to find a pronounced correlation between the superconducting gap and the bosonic coupling strength near the Brillouin zone boundary in Bi₂Sr₂CaCu₂O_8+δ The bosonic coupling strength rapidly increases from the overdoped Fermi liquid regime to the optimally doped strange metal, concomitant with the quadrupled superconducting gap and the doubled gap-to-T _c ratio across the pseudogap boundary. This synchronized lattice and electronic response suggests that the effects of electronic interaction and the electron-phonon coupling (EPC) reinforce each other in a positive-feedback loop upon entering the strange-metal regime, which in turn drives a stronger superconductivity.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.