Possible spin liquid state in a novel triangular lattice antiferromagnet

An intricate interplay between emergent degrees of freedom in rare-earth-based geometrically frustrated magnets represents a promising platform for the search for enigmatic quantum spin liquids (QSL). Our recent study on a novel class of structurally perfect rare-earth-based triangular lattice family has revealed NdTa7O19 as a promising candidate for a QSL stabilized by the strong Ising anisotropy. Herein, we focus on a novel triangular lattice antiferromagnet HoTa7O19, from this family. Our preliminary magnetization and specific heat data do not show any signature of spin-freezing or magnetic ordering down to 75 mK despite a sizable antiferromagnetic interaction, Jex≈ 2 K between Ho3+ spins. Interestingly, the specific heat data shows a broad maximum around 1 K and another broad anomaly at 0.2 K possibly related to short-range spin correlations. This calls for more sensitive local-probe magnetic investigations that could unambiguously confirm the spin-liquid ground state and characterize the corresponding magnetic excitations at very low temperatures. Given the strongly localized nature of 4f orbitals, the exchange interactions of this rare-earth frustrated magnet are typically in the sub-Kelvin range. We plan to conduct the μSR experiment in the millikelvin range to investigate the possible spin liquid state and associated excitations.