@article{35af6ac1d7df47569180404808d61cfa,
title = "Atomically resolved spectroscopic study of Sr2 IrO 4: Experiment and theory",
abstract = "Particularly in Sr2 IrO 4, the interplay between spin-orbit coupling, bandwidth and on-site Coulomb repulsion stabilizes a J eff = 1/2 spin-orbital entangled insulating state at low temperatures. Whether this insulating phase is Mott-or Slater-type, has been under intense debate. We address this issue via spatially resolved imaging and spectroscopic studies of the Sr 2 IrO 4 surface using scanning tunneling microscopy/spectroscopy (STM/S). STS results clearly illustrate the opening of an insulating gap (150 ∼ 250{\^a}meV) below the N{\'e}el temperature (T N), in qualitative agreement with our density-functional theory (DFT) calculations. More importantly, the temperature dependence of the gap is qualitatively consistent with our DFT + dynamical mean field theory (DMFT) results, both showing a continuous transition from a gapped insulating ground state to a non-gap phase as temperatures approach T N. These results indicate a significant Slater character of gap formation, thus suggesting that Sr 2 IrO 4 is a uniquely correlated system, where Slater and Mott-Hubbard-type behaviors coexist.",
author = "Qing Li and Guixin Cao and Satoshi Okamoto and Jieyu Yi and Wenzhi Lin and Sales, {Brian C.} and Jiaqiang Yan and Ryotaro Arita and Jan Kune{\v s} and Kozhevnikov, {Anton V.} and Eguiluz, {Adolfo G.} and Masatoshi Imada and Zheng Gai and Minghu Pan and Mandrus, {David G.}",
note = "Funding Information: This research was conducted (MP, QL, ZG) at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. Research was supported (GXC, SO, WL, JYY, BCS, JQY, DGM) by the U.S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division. RA and MI were supported by MEXT Japan and Strategic Programs for Innovative Research (SPIRE), MEXT, and the Computational Materials Science Initiative (CMSI), Japan. JK was supported by the Grant No. 13-25251S of the Grant Agency of the Czech Republic. AVK acknowledges the computational resources of the CSCS and of the NCCS and the CNMS at ORNL, which are sponsored by the respective facilities divisions of the offices of ASCR and BES of the U.S. DOE. AGE was supported by NSF Grant No. OCI-0904972.",
year = "2013",
doi = "10.1038/srep03073",
language = "English",
volume = "3",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
}