Universal waterfalls-like feature in the spectral function of high temperature superconductors

TL;DR

This study reveals a universal high-energy anomaly in the spectral function of high-temperature cuprate superconductors, characterized by two new energy scales and a distinctive momentum-space feature, shedding light on the interactions underlying high Tc superconductivity.

Contribution

It reports the discovery of a universal high-energy anomaly in cuprates' spectral function, identified through extensive ARPES experiments across multiple families.

Findings

Identification of two high energy scales, E1 and E2.

Observation of spectral function pinning along a diamond boundary.

Unveiling a link between doped oxygen holes and quasiparticles.

Abstract

By performing high resolution angle resolved photoemission spectroscopy (ARPES) experiments on four different families of p-type cuprates, over an energy range much bigger than investigated before, we report the discovery of a universal high energy anomaly in the spectral function. This anomaly is characterized by the presence of two new high energy scales $E_1= 0.35-0.45$eV and $E_2=0.8-0.9$eV and the pinning of the main ARPES spectral function along the boundary of a diamond in the momentum space. This anomaly unveils a missing link between the doped oxygen holes and the quasiparticles, providing a full range of relevant interaction to the high Tc problem.