single crystal with Jeff=3/2 ground state magnetic molecular*

The geometrical spin frustration in the tetramer of lacunar spinel is a good subject for exploring the quantum spin liquid. In tantalum lacunar spinel, GaTa₄Se8, there are molecular J_eff = 3/2 ground state and curious non-magnetic state with Jahn-Teller distortion [1]. Recently, we successfully grown the high quality of GaTa₄Se₈ single crystal, and studied by characterization of physical properties and inelastic neutron scattering. Temperature dependence of those characterization shows the difference between structure transition with orbital ordering, and indicates that gapped excitation already exists at higher temperature than orbital ordering temperature T_S ~53 K.

[1] M Jeong et al., Nature comms., 8, 782 (2018)