TY - JOUR
T1 - Pressure-driven collapse of the relativistic electronic ground state in a honeycomb
AU - Clancy, J. Patrick
AU - Gretarsson, Hlynur
AU - Sears, Jennifer A.
AU - Singh, Yogesh
AU - Desgreniers, Serge
AU - Mehlawat, Kavita
AU - Layek, Samar
AU - Rozenberg, Gregory Kh
AU - Ding, Yang
AU - Upton, Mary H.
AU - Casa, Diego
AU - Chen, Ning
AU - Im, Junhyuck
AU - Lee, Yongjae
AU - Yadav, Ravi
AU - Hozoi, Liviu
AU - Efremov, Dmitri
AU - Van Den Brink, Jeroen
AU - Kim, Young June
N1 - Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Honeycomb-lattice quantum magnets with strong spin-orbit coupling are promising candidates for realizing a Kitaev quantum spin liquid. Although iridate materials such as Li2IrO3 and Na2IrO3 have been extensively investigated in this context, there is still considerable debate as to whether a localized relativistic wavefunction (J eff = 1/2) provides a suitable description for the electronic ground state of these materials. To address this question, we have studied the evolution of the structural and electronic properties of α-Li2IrO3 as a function of applied hydrostatic pressure using a combination of X-ray diffraction and X-ray spectroscopy techniques. We observe striking changes even under the application of only small hydrostatic pressure (P ≤ 0.1 GPa): A distortion of the Ir honeycomb lattice (via X-ray diffraction), a dramatic decrease in the strength of spin-orbit coupling effects (via X-ray absorption spectroscopy), and a significant increase in non-cubic crystal electric field splitting (via resonant inelastic X-ray scattering). Our data indicate that α-Li2IrO3 is best described by a J eff = 1/2 state at ambient pressure, but demonstrate that this state is extremely fragile and collapses under the influence of applied pressure.
AB - Honeycomb-lattice quantum magnets with strong spin-orbit coupling are promising candidates for realizing a Kitaev quantum spin liquid. Although iridate materials such as Li2IrO3 and Na2IrO3 have been extensively investigated in this context, there is still considerable debate as to whether a localized relativistic wavefunction (J eff = 1/2) provides a suitable description for the electronic ground state of these materials. To address this question, we have studied the evolution of the structural and electronic properties of α-Li2IrO3 as a function of applied hydrostatic pressure using a combination of X-ray diffraction and X-ray spectroscopy techniques. We observe striking changes even under the application of only small hydrostatic pressure (P ≤ 0.1 GPa): A distortion of the Ir honeycomb lattice (via X-ray diffraction), a dramatic decrease in the strength of spin-orbit coupling effects (via X-ray absorption spectroscopy), and a significant increase in non-cubic crystal electric field splitting (via resonant inelastic X-ray scattering). Our data indicate that α-Li2IrO3 is best described by a J eff = 1/2 state at ambient pressure, but demonstrate that this state is extremely fragile and collapses under the influence of applied pressure.
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U2 - 10.1038/s41535-018-0109-0
DO - 10.1038/s41535-018-0109-0
M3 - Article
AN - SCOPUS:85051543264
SN - 2397-4648
VL - 3
JO - npj Quantum Materials
JF - npj Quantum Materials
IS - 1
M1 - 35
ER -