Pressure-tuning of bond-directional exchange interactions and magnetic frustration in hyperhoneycomb iridate β-Li2IrO3
- Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Argonne National Lab. (ANL), Argonne, IL (United States); Univ. College London, London (United Kingdom)
- Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
- Argonne National Lab. (ANL), Argonne, IL (United States); Center for High Pressure Science & Technology Advanced Research (HPSTAR), Shanghai (China); Chinese Academy of Sciences (CAS), Beijing (China)
- Argonne National Lab. (ANL), Argonne, IL (United States); Brazilian Synchrotron Light Lab. (LNLS), Campinas (Brazil)
- Argonne National Lab. (ANL), Argonne, IL (United States); Washington Univ., St. Louis, MO (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
- Washington Univ., St. Louis, MO (United States)
- Univ. of Toronto, Toronto, ON (Canada)
- Univ. of Toronto, Toronto, ON (Canada); Canadian Institute for Advanced Research/Quantum Materials Program, Toronto, ON (Canada)
- Center for High Pressure Science & Technology Advanced Research (HPSTAR), Shanghai (China); Carnegie Inst. of Washington, Argonne, IL (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States); Northern Illinois Univ., DeKalb, IL (United States)
- Max Planck Institute for Solid State Research, Stuttgart (Germany); Univ. of Tokyo, Tokyo (Japan)
- Argonne National Lab. (ANL), Argonne, IL (United States)
Here, we explore the response of Ir 5d orbitals to pressure in β-Li2IrO3, a hyperhoneycomb iridate in proximity to a Kitaev quantum spin-liquid (QSL) ground state. X-ray absorption spectroscopy reveals a reconstruction of the electronic ground state below 2 GPa, the same pressure range where x-ray magnetic circular dichroism shows an apparent collapse of magnetic order. The electronic reconstruction, which manifests a reduction in the effective spin-orbit interaction in 5d orbitals, pushes β-Li2IrO3 further away from the pure Jeff = 1/2 limit. Although lattice symmetry is preserved across the electronic transition, x-ray diffraction shows a highly anisotropic compression of the hyperhoneycomb lattice which affects the balance of bond-directional Ir-Ir exchange interactions driven by spin-orbit coupling at Ir sites. An enhancement of symmetric anisotropic exchange over Kitaev and Heisenberg exchange interactions seen in theoretical calculations that use precisely this anisotropic Ir-Ir bond compression provides one possible route to the realization of a QSL state in this hyperhoneycomb iridate at high pressures.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- Argonne National Laboratory, Advanced Photon Source; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Materials Sciences and Engineering Division
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1402077
- Alternate ID(s):
- OSTI ID: 1412661; OSTI ID: 1398826
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 14 Vol. 96; ISSN 0163-1829
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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Magnon-spinon dichotomy in the Kitaev hyperhoneycomb β-Li2IrO3
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