Synthesis and Characterization of a New Kitaev Quantum Spin Liquid Candidate, H₃LiRh₂O₆

The Kitaev quantum spin liquid (KQSL) hosts emergent quasiparticles - localized Z₂ fluxes and itinerant Majorana fermions - that represent one of the most compelling realizations of spin fractionalization and form a potential foundation for fault-tolerant topological quantum computing. In the canonical candidate α-RuCl₃, however, long-range magnetic order at 7 K, driven by non-Kitaev interactions, destabilize the zero-field KQSL state in α-RuCl₃ and confines KQSL to a field-induced regime above 8 T. Other KQSL candidates, including H₃LiIr₂O₆ and (H,Li)₆Ru₂O₆, exhibit gapless owing to vacancy disorder and stacking faults that localize low-energy Majorana excitations. Here we report a new Rh-based honeycomb compound, H₃LiRh₂O₆, that exhibits no magnetic ordering down to 78 mK. The zero-field heat capacity displays an exponential low-temperature behaviour, a robust T²-dependence at intermediate temperatures, and a characteristic two-peak structure accompanied by a two-step entropy release. These signatures suggest a gapped ground state and possible KQSL signatures. Scaling analysis further uncovers defect-induced localization of low-energy Majorana fermions, consistent with observations in other Kitaev compounds. Inelastic neutron-scattering experiments can directly probe these emergent Majorana excitations.