相关论文: Energy of the nearest neighbor RVB state by system…
The Gutzwiller projection of the Schwinger-boson mean-field solution of the 2-d spin-1/2 antiferromagnet in a square lattice is shown to produce the optimized, parameter-free RVB ground state. We get $-0.6688J$/site and $0.311$ for the…
We use the diagram technique for spin operators to calculate Green's functions and observables of the spin-1/2 quantum Heisenberg antiferromagnet on a square lattice. The first corrections to the self-energy and interaction are taken into…
The spin-1/2 Heisenberg model on an anisotropic triangular lattice is considered in the mean-field RVB approximation. The analytical estimates for the critical temperatures of the longitudinal s-RVB state (the upper one) and the 2D s-RVB…
Several ground state properties of the square-lattice $S=1/2$ Heisenberg antiferromagnet are computed (the energy, order parameter, spin stiffness, spinwave velocity, long-wavelength susceptibility, and staggered susceptibility) using…
We present an analytical result for the ratio of the physical correlation length in a 2D Heisenberg antiferromagnet on a square lattice, and the one which is actually computed in numerical simulations. This last correlation length is…
We present a Schwinger-boson approach for the RVB state of the spin-1/2 Heisenberg antiferromagnet on a triangular lattice. It is shown that Gutzwiller projection of the mean-field state that includes both antiferromagnetic and…
We investigate the spin dynamics of the square-lattice spin-1/2 Heisenberg antiferromagnet by means of an improved mean field Schwinger boson calculation. By identifying both, the long range N\'eel and the RVB-like components of the ground…
We develop the formalism for calculating arbitrary expectation values for any extensive lattice Hamiltonian system using a new analytic Lanczos expansion, or plaquette expansion, and a recently proved exact theorem for ground state…
The ground state energy and the singlet-triplet energy gap of the antiferromagnetic Heisenberg model on a ladder is investigated using a mean field theory and the density matrix renormalization group. Spin wave theory shows that the…
We introduce a generic method for computing groundstates that is applicable to a wide range of spatially anisotropic 2D many-body quantum systems. By representing the 2D system using a low-energy 1D basis set, we obtain an effective 1D…
We perform numerical simulations of the 2-d antiferromagnetic quantum Heisenberg model using an efficient cluster algorithm. Comparing the finite size and finite temperature effects of various quantities with recent results from chiral…
A simple approach to estimation of the ground state energy of quantum antiferromagnets is developed, based on the approximation that quantum fluctuations around different bonds are independent. The ground state energy estimates are as good…
The staggered magnetization of the Heisenberg antiferromagnet in two dimensions can be systematically approximated by a 1/N expansion. Cancellation between self energy diagrams leads to a Luttinger-like theorem for the ground state. We…
We calculate ground state properties (energy, magnetization, susceptibility) and one-particle spectra for the $S = 1$ Heisenberg antiferromagnet with easy-axis or easy-plane single site anisotropy, on the square lattice. Series expansions…
We calculate the ground state energies of a system of two dipolar fermions trapped in a harmonic oscillator potential. The dipoles are assumed to be aligned parallel to each other. We perform the calculations of ground state energy as a…
Constrained Relativistic Mean Field (RMF) calculations have been carried out to estimate excitation energies relative to the ground state for superdeformed bands in the mass regions A $\sim$ 190 and A $\sim$ 150. It is shown that RMF theory…
We study a variational wave function for the ground state of the two-dimensional S=1/2 Heisenberg antiferromagnet in the valence bond basis. The expansion coefficients are products of amplitudes h(x,y) for valence bonds connecting spins…
We consider two-component fermions on the lattice in the unitarity limit. This is an idealized limit of attractive fermions where the range of the interaction is zero and the scattering length is infinite. Using Euclidean time projection,…
The high-density electron gas in a strong magnetic field B and at zero temperature is investigated. The quantum strong-field limit is considered in which only the lowest Landau level is occupied. It is shown that the perturbation series of…
In this work, a long-range resonating valence bond state is proposed as a variational wave function for the ground state of the $S=1/2$ antiferromagnetic Heisenberg model on the honeycomb lattice. Employing Variational Monte Carlo (VMC)…