CM In the literature: contested

Nature of the intermediate phase of the triangular-lattice Hubbard model

In plain words

On a triangular lattice, between the metal at weak repulsion and the magnet at strong repulsion, there may be a quantum spin liquid, a state in which spins keep fluctuating at zero temperature.

Precise statement

For the half-filled triangular-lattice Hubbard model, determine whether the intermediate window found in cylinder DMRG (approximately $8.5 < U/t < 10.5$, with boundaries that depend on cylinder width) is a chiral spin liquid, a gapless spin liquid, a weakly ordered magnet, or a finite-width artifact in the two-dimensional limit. An answer is the ground-state classification (order parameters, scalar chirality, topological degeneracy) with controlled width extrapolation.

What would settle it

Consistent results from DMRG on cylinders of increasing circumference and from independent two-dimensional methods for the chirality and spin order parameters.

Status in the literature

Cylinder DMRG (2020) found a chiral spin liquid in the intermediate window; its survival in two dimensions is not established.