The pseudogap, d-wave superconductivity and electron-boson coupling are three intertwined key ingredients in the phase diagram of the cuprates. Sr2IrO4 is a 5d-electron counterpart of the cuprates in which both the pseudogap and a d-wave instability have been observed. Here, we report spectroscopic evidence for the presence of the third key player in electron-doped Sr2IrO4: electron-boson coupling. A kink in nodal dispersion is observed with an energy scale of ~50 meV. The strength of the kink changes with doping, but the energy scale remains the same. These results provide the first noncuprate platform for exploring the relationship between the pseudogap, d-wave instability and electron-boson coupling in doped Mott insulators.
@article{arxiv.1912.05332,
title = {Spectroscopic evidence for electron-boson coupling in electron-doped Sr$_2$IrO$_4$},
author = {Yong Hu and Xiang Chen and S. -T. Peng and C. Lane and M. Matzelle and Z. -L. Sun and M. Hashimoto and D. -H. Lu and E. F. Schwier and M. Arita and T. Wu and R. S. Markiewicz and K. Shimada and X. -H. Chen and Z. -X. Shen and A. Bansil and S. D. Wilson and J. -F. He},
journal= {arXiv preprint arXiv:1912.05332},
year = {2019}
}