Quantum Monte Carlo study on the phase transition for a generalized two-dimensional staggered dimerized Heisenberg model

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摘要：

In order to gain a deeper understanding of the quantum criticality in the explicitly staggered dimerized Heisenberg models,we study a generalized staggered dimer model named the J0-J1-J2 model,which corresponds to the staggered J-J ' model on a square lattice and a honeycomb lattice when J1/J0 equals 1 and 0,respectively.Using the quantum Monte Carlo method,we investigate all the quantum critical points of these models with J1/J0 changing from 0 to 1 as a function of coupling ratio α=J2/J0.We extract all the critical values of the coupling ratio αc for these models,and we also obtain the critical exponents ν,β/ν,and η using different finite-size scaling anstz,.All these exponents are not consistent with the three-dimensional Heisenberg universality class,indicating some unconventional quantum ciritcial points in these models.

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Theoretical or Mathematical/ copper compounds critical exponents critical points Heisenberg model high-temperature superconductors Monte Carlo methods Neel temperature t-J model/ quantum Monte Carlo method phase transition generalized staggered dimer model generalized Heisenberg model J-J' model square lattice honeycomb lattice quantum critical points critical exponents finite size scaling ansatz three-dimensional Heisenberg universality class Neel transition high-temperature superconductors CuO 2/ A7510J Heisenberg and other quantized localized spin models (magnetism) A7530K Magnetic phase boundaries A6185 Modelling and computer simulation of solid structure A6460F Equilibrium properties near critical points, critical exponents A7430C Magnetic properties of superconductors A7470V Perovskite phase and other high-temperature superconductors/ CuO2/bin O2/bin Cu/bin O/bin