README.md

RimuLegacyHamiltonians

This repository contains legacy Hamiltonians for Rimu.jl. These Hamiltonians are already or will eventually be superseeded by more general Hamiltonian types.

Installing RimuLegacyHamiltonians

The package is currently not registered. It can be installed from the repository on GitHub.com. It is meant to be used with Rimu.jl. Hit the ] key at the Julia REPL to get into Pkg mode and type

pkg> add "https://github.com/RimuQMC/RimuLegacyHamiltonians.jl" Rimu

Usage

The package is now installed and can be imported with

julia> using Rimu, RimuLegacyHamiltonians

Exported types

BoseFS2C # address type with two bosonic components 
BoseHubbardMom1D2C # Hubbard chain in momentum space for two-component bosons
BoseHubbardReal1D2C # Hubbard chain in real space for two-component bosons

Example

julia> using RimuLegacyHamiltonians; import Rimu

julia> fs = BoseFS2C((1,2,1),(0,1,0))
BoseFS2C(BoseFS{4,3}(1, 2, 1), BoseFS{1,3}(0, 1, 0))

julia> h = BoseHubbardMom1D2C(fs)
BoseHubbardMom1D2C(BoseFS2C(BoseFS{4,3}(1, 2, 1), BoseFS{1,3}(0, 1, 0)); ua=1.0, ub=1.0, ta=1.0, tb=1.0, v=1.0)

julia> ep = Rimu.ExactDiagonalizationProblem(h)
ExactDiagonalizationProblem(
  BoseHubbardMom1D2C(BoseFS2C(BoseFS{4,3}(1, 2, 1), BoseFS{1,3}(0, 1, 0)); ua=1.0, ub=1.0, ta=1.0, tb=1.0, v=1.0),
  nothing;
  NamedTuple()...
)

julia> Rimu.solve(ep)
EDResult for algorithm LinearAlgebraSolver() with 15 eigenvalue(s),
  values = [-6.9403, -0.56511, -0.215232, 0.715199, 2.51409, 2.7328, 4.1605, 4.17157, 5.83875, 6.63714, 7.15727, 8.19517, 8.86239, 9.82843, 11.9073],
  and vectors of length 15.
  Convergence info: "Dense matrix eigensolver solution from `LinearAlgebra.eigen`", with howmany = 15 eigenvalues requested.
  success = true.