Is there a pure quantum spin liquid?

Sketch of quantum spin liquid (QSL) on the triangular lattice, lattice structure showing the position of magnetic Yb3+ ions in NaYbCh2 (Ch = O, S, Se, etc), and the droplet-like ferrimagnetic clusters in a QSL sea

Spin liquids are exotic materials where the magnetic order is absent due to fluctuations at any finite temperature less than the spin interaction. Their occurrence is attributed to a high degree of ground state degeneracy. Wannier showed in 1950 that such a large degeneracy of ground state can theoretically take place in a two-dimensional (2D) triangular lattice with Ising spins, a classically geometrical frustrated lattice mode. So far, the geometrically frustrated lattice has a large family of systems: edge-shared triangles as a triangular lattice and corner-shared triangles as a kagomé lattice in a 2D system and corner-sharing tetrahedra as a pyrochlore lattice in a three-dimensional system, etc.