Ubiquitous Coexisting Electron-Mode Couplings in High Temperature Cuprate Superconductors

Abstract

In conventional superconductors, the electron-phonon coupling plays a dominant role in pairing the electrons and generating superconductivity. In high temperature cuprate superconductors, the existence of the electron coupling with phonons and other boson modes and its role in producing high temperature superconductivity remain unclear. The evidence of the electron-boson coupling mainly comes from the angle-resolved photoemission (ARPES) observations of the ~70meV nodal dispersion kink and the ~40meV antinodal kink. However, the reported results are sporadic and the nature of the involved bosons are still under debate. Here we report new findings of ubiquitous two coexisting electron-mode couplings in cuprate superconductors. By taking ultra-high resolution laser-based ARPES measurements, combined with the improved second derivative analysis method, we discovered that the electrons are coupled simultaneously with two sharp phonon modes with energies of ~70meV and ~40meV in different superconductors with different doping levels, over the entire momentum space and at different temperatures above and below the superconducting transition temperature. The observed electron-phonon couplings are unusual because the associated energy scales do not exhibit an obvious change across the superconducting transition. We further find that the well-known "peak-dip-hump" structure, which has long been considered as a hallmark of superconductivity, is also omnipresent and consists of finer structures that originates from electron coupling with two sharp phonon modes. These comprehensive results provide a unified picture to reconcile all the reported observations and pinpoint the origin of the electron-mode couplings in cuprate superconductors. They provide key information to understand the role of the electron-phonon coupling in generating high temperature superconductivity.

References in corpus (14)

• Strength of the Spin-Fluctuation-Mediated Pairing Interaction in a High-Temperature Superconductor
• Development of a Vacuum Ultra-Violet Laser-Based Angle-Resolved Photoemission System with a Super-High Energy Resolution Better Than 1 meV
• Kinks in the dispersion of strongly correlated electrons
• Point nodes persisting far beyond Tc in Bi2212
• Identification of a New Form of Electron Coupling in Bi2Sr2CaCu2O8 Superconductor by Laser-Based Angle-Resolved Photoemission
• Photoemission kinks and phonons in cuprates
• Momentum dependence of the electron-phonon coupling and self-energy effects in YBa_2Cu_3O_7 within the local density approximation
• Puddle formation, persistent gaps, and non-mean-field breakdown of superconductivity in overdoped (Pb,Bi)2Sr2CuO6+δ
• Unmasking the Origin of Kinks in the Photoemission Spectra of Cuprate Superconductors
• Superconductivity-Induced Self-Energy Evolution of the Nodal Electron of Optimally-Doped Bi2212
• Growth, characterization and physical properties of high-quality large single crystals of Bi${}_2$Sr${}_{2-x}$La${}_x$CuO${}_6$ high-temperature superconductors
• Disappearance of Superconductivity and a Concomitant Lifshitz Transition in Heavily-Overdoped Bi2Sr2CuO6 Superconductor Revealed by Angle-Resolved Photoemission Spectroscopy
• Extracting correlation effects from Momentum-Resolved Electron Energy Loss Spectroscopy (M-EELS): Synergistic origin of the dispersion kink in Bi${}_{2.1}$Sr${}_{1.9}$CaCu${}_2$O${}_{8+x}$
• What do the two times in two-time correlation functions mean for interpreting tr-ARPES?

Cited by in corpus (7)

• Dichotomy in Low- and High-energy Band Renormalizations in Trilayer Nickelate $L{a}_{4}N{i}_3{O}_{10}$: a Comparison with Cuprates
• van Hove Singularity-Driven Emergence of Multiple Flat Bands in Kagome Superconductors
• Role of many phonon modes on the high-temperature linear-in-$T$ electronic resistivity
• Expansion of Momentum Space and Full 2$\pi$ Solid Angle Photoelectron Collection in Laser-Based Angle-Resolved Photoemission Spectroscopy by Applying Sample Bias
• Doping Evolution of Nodal Electron Dynamics in Trilayer Cuprate Superconductor Bi${}_2$Sr${}_2$Ca${}_2$Cu${}_3$O${}_{10+\delta }$ Revealed by Laser-Based Angle-Resolved Photoemission Spectroscopy
• BCS-BEC crossover driven by small Fermi pockets of a high-Tc cuprate superconductor
• Interfacial Strain Modulated Correlated Plasmons in La1.85Sr0.15CuO4 and Their Role in High-temperature Superconductivity