Spectroscopic Evidence for Electron-Boson Coupling in Electron-Doped Sr_{2}IrO_{4}

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• The cuprates exhibit a complex phase diagram involving pseudogap, d-wave superconductivity, and electron-boson coupling.
• Sr_{2}IrO_{4}, a 5d-electron analog of cuprates, shows pseudogap and d-wave instability.

Purpose of the Study:

• To investigate the presence and characteristics of electron-boson coupling in electron-doped Sr_{2}IrO_{4}.
• To explore Sr_{2}IrO_{4} as a non-cuprate platform for studying fundamental electronic interactions.

Main Methods:

• Spectroscopic analysis of electron-doped Sr_{2}IrO_{4}.
• Observation and characterization of kinks in nodal dispersion.

Main Results:

• Spectroscopic evidence confirms electron-boson coupling in electron-doped Sr_{2}IrO_{4}.
• A kink in nodal dispersion was observed at an energy scale of approximately 50 meV.
• The strength of this kink varied with doping, while its energy scale remained constant.

Conclusions:

• Electron-boson coupling is identified as a key factor in electron-doped Sr_{2}IrO_{4}.
• Sr_{2}IrO_{4} serves as the first non-cuprate system to study the relationship between pseudogap, d-wave instability, and electron-boson coupling.
• These findings advance the understanding of doped Mott insulators.