Efficient matrix-product-state preparation of highly entangled trial states: Weak Mott insulators on the triangular lattice revisited Article Swipe
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· 2020
· Open Access
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· DOI: https://doi.org/10.48550/arxiv.2009.12435
· OA: W3088444106
Using tensor network states to unravel the physics of quantum spin liquids in minimal, yet generic microscopic spin or electronic models remains notoriously challenging. A prominent open question concerns the nature of the insulating ground state of two-dimensional half-filled Hubbard-type models on the triangular lattice in the vicinity of the Mott metal-insulator transition, a regime which can be approximated microscopically by a spin-1/2 Heisenberg model supplemented with additional "ring-exchange" interactions. Using a novel and efficient state preparation technique whereby we initialize full density matrix renormalization group (DMRG) calculations with highly entangled Gutzwiller-projected Fermi surface trial wave functions, we show -- contrary to previous works -- that the simplest triangular lattice $J$-$K$ spin model with four-site ring exchange likely does not harbor a fully gapless U(1) spinon Fermi surface (spin Bose metal) phase on four- and six-leg wide ladders. Our methodology paves the way to fully resolve with DMRG other controversial problems in the fields of frustrated quantum magnetism and strongly correlated electrons.
