Atomically resolved spectroscopic study of Sr2 IrO 4: Experiment and theory

Qing Li; Guixin Cao; Satoshi Okamoto; Jieyu Yi; Wenzhi Lin; Brian C. Sales; Jiaqiang Yan; Ryotaro Arita; Jan Kuneš; Anton V. Kozhevnikov; Adolfo G. Eguiluz; Masatoshi Imada; Zheng Gai; Minghu Pan; David G. Mandrus

doi:10.1038/srep03073

Atomically resolved spectroscopic study of Sr₂ IrO ₄: Experiment and theory

Qing Li
, Guixin Cao
, Satoshi Okamoto
, Jieyu Yi
, Wenzhi Lin
, Brian C. Sales
, Jiaqiang Yan
, Ryotaro Arita
, Jan Kuneš
, Anton V. Kozhevnikov
, Adolfo G. Eguiluz
, Masatoshi Imada
, Zheng Gai
, Minghu Pan
, David G. Mandrus

Correlated Electron Materials

Research output: Contribution to journal › Article › peer-review

49 Scopus citations

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 ∼ 250âmeV) below the Néel 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.

Original language	English
Article number	3073
Journal	Scientific Reports
Volume	3
DOIs	https://doi.org/10.1038/srep03073
State	Published - 2013

Funding

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.

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@article{932c7ac8b1f5493d892cd61b92741214,

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.\}",

year = "2013",

doi = "10.1038/srep03073",

language = "English",

volume = "3",

journal = "Scientific Reports",

issn = "2045-2322",

publisher = "Nature Research",

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TY - JOUR

T1 - Atomically resolved spectroscopic study of Sr2 IrO 4

T2 - Experiment and theory

AU - Li, Qing

AU - Cao, Guixin

AU - Okamoto, Satoshi

AU - Yi, Jieyu

AU - Lin, Wenzhi

AU - Sales, Brian C.

AU - Yan, Jiaqiang

AU - Arita, Ryotaro

AU - Kuneš, Jan

AU - Kozhevnikov, Anton V.

AU - Eguiluz, Adolfo G.

AU - Imada, Masatoshi

AU - Gai, Zheng

AU - Pan, Minghu

AU - Mandrus, David G.

PY - 2013

Y1 - 2013

N2 - 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 ∼ 250âmeV) below the Néel 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.

AB - 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 ∼ 250âmeV) below the Néel 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.

UR - https://www.scopus.com/pages/publications/84886992429

U2 - 10.1038/srep03073

DO - 10.1038/srep03073

M3 - Article

AN - SCOPUS:84886992429

SN - 2045-2322

VL - 3

JO - Scientific Reports

JF - Scientific Reports

M1 - 3073

ER -

Atomically resolved spectroscopic study of Sr₂ IrO ₄: Experiment and theory

Abstract

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