For the one-dimensional Hubbard model subject to periodic boundary conditions we construct a unitary transformation between basis states so that open boundary conditions apply for the transformed Hamiltonian. Despite the fact that the one-particle and two-particle interaction matrices link nearest and next-nearest neighbors only, the performance of the density-matrix renormalization-group (DMRG) method for the transformed Hamiltonian does not improve. Some of the new interactions act as independent quantum channels, which generate the same level of entanglement as periodic boundary conditions in the original formulation of the Hubbard model. We provide a detailed analysis of these channels and show that, apart from locality of the interactions, the performance of DMRG is effected significantly by the number and the strength of the quantum channels that entangle the DMRG blocks.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Nov 22 2006|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics