Real-space renormalization-group studies of low-dimensional quantum antiferromagnets
- Laboratoire de Physique Quantique, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse CEDEX (France)
- Department of Physics, Center for Materials Research and Technology Supercomputer Computations Research Isntitute, Florida State University, Tallahassee, Florida 32306 (United States)
We study the ground state of one- and two-dimensional (square-lattice) spin-1/2 quantum antiferromagnets using a numerical real-space renormalization-group (RG) approach. In our RG approach we consider blocks of various sizes but with an odd number of sites; we retain only the doublet ground state and we integrate out the higher-energy states by means of second-order quasidegenerate perturbation theory. That is, we assume that the role of the excited states of a block, in the RG iteration process, is to renormalize the effective coupling parameters between blocks. We compute the ground-state energy of a spin-1/2 linear chain for various block sizes and find close agreement with the Bethe-ansatz exact solution. In the case of the spin-1/2 square-lattice quantum antiferromagnet, the obtained ground-state energy is in reasonable agreement with the available numerical estimates.
- DOE Contract Number:
- FC05-85ER25000
- OSTI ID:
- 6237029
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Vol. 48:2; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermal tensor renormalization group simulations of square-lattice quantum spin models
Moments of the Raman spectrum of the two-dimensional Heisenberg antiferromagnet