Smooth boundary conditions for quantum lattice systems.

  title={Smooth boundary conditions for quantum lattice systems.},
  author={Vekic and White},
  journal={Physical review letters},
  volume={71 26},
  • Vekic, White
  • Published 22 October 1993
  • Mathematics
  • Physical review letters
We introduce a new type of boundary conditions, smooth boundary conditions, for numerical studies of quantum lattice systems. In a number of circumstances, these boundary conditions have substantially smaller finite-size effects than periodic or open boundary conditions. They can be applied to nearly any short-ranged Hamiltonian system in any dimensionality and within almost any type of numerical approach 
Calculating Green Functions from Finite Systems
This work compares various discretization schemes for impurity problems, i.e. a small system coupled to leads, and discusses the importance of choosing the right single particle basis when calculating bulk spectral functions.
Finite-temperature density matrix renormalization using an enlarged Hilbert space
We apply a generalization of the time-dependent density matrix renormalization group (DMRG) to study finite-temperature properties of several quantum spin chains, including the frustrated
Energetic damping in electronic transport simulations on finite systems
In this paper, an implementation of energetic damping for fermionic transport simulations which respects particle conservation is presented. For this, nonhermitian terms in the Hamiltonian of the
Critical entanglement for the half-filled extended Hubbard model
We study the ground state of the one-dimensional extended Hubbard model at half-filling using the entanglement entropy calculated by Density Matrix Renormalization Group (DMRG) techniques. We apply a
Sine-square deformation and supersymmetric quantum mechanics
We investigate the sine-square deformation (SSD) of free fermions in one-dimensional continuous space. On the basis of supersymmetric quantum mechanics, we prove the correspondence between the
Hyperbolic Deformation Applied to S = 1 Spin Chains - Scaling Relation in Excitation Energy -
We investigate excitation energies of hyperbolically deformed S = 1 spin chains, which are specified by the local energy scale f_j^{~} = \cosh j \lambda, where j is the lattice index and \lambda is
Inverse mean field theories.
The extraction of mean field single particle Hamiltonians from a many body wave function of a fermionic system can be used to decide whether a density matrix renormalization group calculation for interacting fermions has converged to the true ground state.
Exact ground state of the sine-square deformed XY spin chain
We study the sine-square deformed quantum XY chain with open boundary conditions in which the interaction strength at the position x in the chain of length L is proportional to the function . The
From conformal to volume-law for the entanglement entropy in exponentially deformed critical spin 1/2 chains
An exponential deformation of 1D critical Hamiltonians gives rise to ground states whose entanglement entropy satisfies a volume law. This effect is exemplified in the XX and Heisenberg models. In