Recent efforts were focused on the search for honeycomb antiferromagnets that realize Kitaev model in two dimensions. Despite showing sizable Kitaev couplings, Na2IrO3 and α-Li2IrO3 undergo long-range magnetic ordering at low temperatures and prove hard to be tuned by pressure, as compression leads to a dimerization instability and renders α-Li2IrO3 non-magnetic above 3.7 GPa. Here, I will present recent results on the pressurized hyperhoneycomb iridate β-Li2IrO3 and argue that this compound can be tuned to a classical spin liquid state triggered by the reduction in the nearest-neighbor Kitaev term K and the enhancement of the off-diagonal anisotropy Γ. We find that above 1.4 GPa pressurized β-Li2IrO3 separates into a mixture of dynamic and frozen spins representing a partially frozen spin liquid, as expected in a system where spin dynamics is supported by thermal rather than quantum fluctuations. I will further show how Kitaev magnetism is realized in three-dimensional frameworks of Ir4+ hexahalides that can be chemically tuned even at ambient pressure, thus giving rise to a variety of intertwined structural and magnetic instabilities.Financial support by the Alexander von Humboldt Foundation and German Science Foundation (TRR80) is acknowledged.
APS March Meeting Abstracts
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