Hopping-Induced Ground-State Magnetism in 6H Perovskite Iridates

@article{ ISI:000473311400013,
Author = {Nag, A. and Bhowal, S. and Sala, M. Moretti and Efimenko, A. and
   Dasgupta, I and Ray, Sugata},
Title = {{Hopping-Induced Ground-State Magnetism in 6H Perovskite Iridates}},
Journal = {{PHYSICAL REVIEW LETTERS}},
Year = {{2019}},
Volume = {{123}},
Number = {{1}},
Month = {{JUL 1}},
Abstract = {{Investigation of elementary excitations has advanced our understanding
   of many-body physics governing most physical properties of matter.
   Recently spin-orbit excitons have drawn much attention, whose
   condensates near phase transitions exhibit Higgs mode oscillations, a
   long-sought-after physical phenomenon {[}A. Jain, et al., Nat. Phys. 13,
   633 (2017)]. These critical transition points, resulting from competing
   spin-orbit coupling (SOC), local crystalline symmetry, and exchange
   interactions, are not obvious in iridium-based materials, where SOC
   prevails in general. Here, we present results of resonant inelastic
   x-ray scattering on a spin-orbital liquid Ba3ZnIr2O9 and three other
   6H-hexagonal perovskite iridates that show magnetism, contrary to the
   nonmagnetic singlet ground state expected due to strong SOC. Our results
   show that substantial hopping between closely placed Ir5+ ions within
   Ir2O9 dimers in these 6H iridates modifies spin-orbit coupled states and
   reduces spin-orbit excitation energies. Here, we are forced to use at
   least a two-site model to match the excitation spectrum going in-line
   with the strong intradimer hopping. Apart from SOC, low-energy physics
   of iridates is thus critically dependent on hopping and may not be
   ignored even for systems havingmoderate hopping, where the excitation
   spectra can be explained using an atomic model. SOC, which is generally
   found to be 0.4-0.5 eV in iridates, is scaled in effect down to similar
   to 0.26 eV for the 6H systems, sustaining the hope of achieving quantum
   criticality by tuning Ir-Ir separation.}},
Publisher = {{AMER PHYSICAL SOC}},
Address = {{ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}},
Type = {{Article}},
Language = {{English}},
Affiliation = {{Nag, A; Ray, S (Corresponding Author), Indian Assoc Cultivat Sci, Sch Mat Sci, Kolkata 700032, India.
   Nag, A.; Ray, Sugata, Indian Assoc Cultivat Sci, Sch Mat Sci, Kolkata 700032, India.
   Bhowal, S.; Dasgupta, I, Indian Assoc Cultivat Sci, Sch Phys Sci, Kolkata 700032, India.
   Sala, M. Moretti; Efimenko, A., ESRF European Synchrotron, 71 Ave Martyrs, F-38000 Grenoble, France.
   Sala, M. Moretti, Politecn Milan, Dipartimento Fis, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy.
   Nag, A., Diamond Light Source, Harwell Campus, Didcot OX11 0DE, Oxon, England.
   Bhowal, S., Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA.}},
DOI = {{10.1103/PhysRevLett.123.017201}},
Article-Number = {{017201}},
ISSN = {{0031-9007}},
EISSN = {{1079-7114}},
Research-Areas = {{Physics}},
Web-of-Science-Categories  = {{Physics, Multidisciplinary}},
Author-Email = {{mssr@iacs.res.in}},
ResearcherID-Numbers = {{Moretti, Marco/AAF-9255-2019
   }},
ORCID-Numbers = {{Moretti, Marco/0000-0002-9744-9976
   Nag, Abhishek/0000-0002-1394-5105}},
Funding-Acknowledgement = {{Department of Science and Technology (DST)Department of Science &
   Technology (India) {[}WTI/2K15/74]; UGCDAE Consortium for Scientific
   Research, Mumbai, India {[}CRS-M-286]; Science and Engineering Research
   Board (SERB), IndiaDepartment of Science & Technology (India)Science
   Engineering Research Board (SERB), India {[}EMR/2016/005925]}},
Funding-Text = {{S. R. and I. D. G. thank the Technical Research Center of IACS. S. R.
   also thanks the Department of Science and Technology (DST) (Project No.
   WTI/2K15/74), UGCDAE Consortium for Scientific Research, Mumbai, India
   (Project No. CRS-M-286) for support, and Jawaharlal Nehru Centre for
   Advanced Scientific Research from the DST-Synchrotron-Neutron project,
   for performing experiments at ESRF (Proposal No. HC-2872). A. N. thanks
   M. P. M. Dean for useful comments about the result. I. D. G. thanks
   Science and Engineering Research Board (SERB), India (Project No.
   EMR/2016/005925) for support.}},
Number-of-Cited-References = {{31}},
Times-Cited = {{2}},
Usage-Count-Last-180-days = {{2}},
Usage-Count-Since-2013 = {{18}},
Journal-ISO = {{Phys. Rev. Lett.}},
Doc-Delivery-Number = {{IF8BC}},
Unique-ID = {{ISI:000473311400013}},
DA = {{2020-12-22}},
}