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Title: Charge partitioning and anomalous hole doping in Rh-doped Sr 2 IrO 4

Abstract

The simultaneous presence of sizable spin-orbit interactions and electron correlations in iridium oxides has led to predictions of novel ground states including Dirac semimetals, Kitaev spin liquids, and superconductivity. Electron and hole doping studies of spin-orbit assisted Mott insulator Sr2IrO4 are being intensively pursued due to extensive parallels with the La2CuO4 parent compound of cuprate superconductors. In particular, the mechanism of charge doping associated with replacement of Ir with Rh ions remains controversial with profound consequences for the interpretation of electronic structure and transport data. Using x-ray absorption near edge structure measurements at the Rh L, K, and Ir L edges we observe anomalous evolution of charge partitioning between Rh and Ir with Rh doping. The partitioning of charge between Rh and Ir sites progresses in a way that holes are initially doped into the J(eff) = 1/2 band at low x only to be removed from it at higher x values. This anomalous hole doping naturally explains the reentrant insulating phase in the phase diagram of Sr2Ir1-x Rh-x O-4 and ought to be considered when searching for superconductivity and other emergent phenomena in iridates doped with 4d elements.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Los Alamos National Laboratory (LANL) - Laboratory Directed Research and Development (LDRL)
OSTI Identifier:
1390814
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 95; Journal Issue: 6
Country of Publication:
United States
Language:
English

Citation Formats

Chikara, S., Fabbris, G., Terzic, J., Cao, G., Khomskii, D., and Haskel, D.. Charge partitioning and anomalous hole doping in Rh-doped Sr2IrO4. United States: N. p., 2017. Web. doi:10.1103/PhysRevB.95.060407.
Chikara, S., Fabbris, G., Terzic, J., Cao, G., Khomskii, D., & Haskel, D.. Charge partitioning and anomalous hole doping in Rh-doped Sr2IrO4. United States. doi:10.1103/PhysRevB.95.060407.
Chikara, S., Fabbris, G., Terzic, J., Cao, G., Khomskii, D., and Haskel, D.. Wed . "Charge partitioning and anomalous hole doping in Rh-doped Sr2IrO4". United States. doi:10.1103/PhysRevB.95.060407.
@article{osti_1390814,
title = {Charge partitioning and anomalous hole doping in Rh-doped Sr2IrO4},
author = {Chikara, S. and Fabbris, G. and Terzic, J. and Cao, G. and Khomskii, D. and Haskel, D.},
abstractNote = {The simultaneous presence of sizable spin-orbit interactions and electron correlations in iridium oxides has led to predictions of novel ground states including Dirac semimetals, Kitaev spin liquids, and superconductivity. Electron and hole doping studies of spin-orbit assisted Mott insulator Sr2IrO4 are being intensively pursued due to extensive parallels with the La2CuO4 parent compound of cuprate superconductors. In particular, the mechanism of charge doping associated with replacement of Ir with Rh ions remains controversial with profound consequences for the interpretation of electronic structure and transport data. Using x-ray absorption near edge structure measurements at the Rh L, K, and Ir L edges we observe anomalous evolution of charge partitioning between Rh and Ir with Rh doping. The partitioning of charge between Rh and Ir sites progresses in a way that holes are initially doped into the J(eff) = 1/2 band at low x only to be removed from it at higher x values. This anomalous hole doping naturally explains the reentrant insulating phase in the phase diagram of Sr2Ir1-x Rh-x O-4 and ought to be considered when searching for superconductivity and other emergent phenomena in iridates doped with 4d elements.},
doi = {10.1103/PhysRevB.95.060407},
journal = {Physical Review B},
number = 6,
volume = 95,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}
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  • The simultaneous presence of sizable spin-orbit interactions and electron correlations in iridium oxides has led to predictions of novel ground states including Dirac semimetals, Kitaev spin liquids, and superconductivity. Electron and hole doping studies of spin-orbit assisted Mott insulator Sr 2IrO 4 are being intensively pursued due to extensive parallels with the La 2CuO 4 parent compound of cuprate superconductors. In particular, the mechanism of charge doping associated with replacement of Ir with Rh ions remains controversial with profound consequences for the interpretation of electronic structure and transport data. Using x-ray absorption near edge structure measurements at the Rh L,more » K, and Ir L edges we observe anomalous evolution of charge partitioning between Rh and Ir with Rh doping. The partitioning of charge between Rh and Ir sites progresses in a way that holes are initially doped into the J eff = 1/2 band at low x only to be removed from it at higher x values. Furthermore, this anomalous hole doping naturally explains the reentrant insulating phase in the phase diagram of Sr 2Ir 1–xRh xO 4 and ought to be considered when searching for superconductivity and other emergent phenomena in iridates doped with 4d elements.« less
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