Kuklov, AProkof'ev, NikolaiSvistunov, Boris2024-04-262024-04-262004-01-01https://hdl.handle.net/20.500.14394/40526This is the pre-published version harvested from ArXiv. The published version is located at http://prl.aps.org/abstract/PRL/v93/i23/e230402We study superfluid-solid zero-temperature transitions in two-dimensional lattice boson-spin models using worm-algorithm Monte Carlo simulations. We observe that such transitions are typically first order with the exception of special high-symmetry points which require fine-tuning in the Hamiltonian parameter space. We present evidence that the superfluid-checkerboard solid and superfluid–valence-bond solid transitions at half-integer filling factor are extremely weak first-order transitions and in small systems can be confused with continuous or high-symmetry points.Physical Sciences and MathematicsWeak First-Order Superfluid-Solid Quantum Phase Transitionsarticle