template.yaml

# Description of the Hilbert space.
basis:
  # Specify the number of spins in the system.
  number_spins: <integer>
  # (OPTIONAL) Restrict the Hilbert space to spin configurations with a
  # particular Hamming weight. (Hamming weight is the number of spin-ups).
  # Omit this field if you do not wish to restrict the Hilbert space to a
  # sector with particular magnetization.
  hamming_weight: 5
  # Specify lattice symmetry generators.
  #
  # For each generator, we have to specify two things: how it permutes
  # lattice sites, and how it affects the phase of the wavefunction.
  #
  # For example, the following specifies translation symmetry for 10-spin chain
  # with eigenvalue ‐1:
  #
  #   symmetries:
  #     - permutation: [1, 2, 3, 4, 5, 6, 8, 9, 0]
  #       sector: 5
  #
  # If you do not wish to use any lattice symmetries, specify an empty list:
  #
  #   symmetries: []
  symmetries:
      # Specify the permutation:
    - permutation: <list-of-integer>
      # Specify the sector.
      #
      # Each permutation P has a finite periodicity N which is the minimal
      # positive integer such that Pᴺ is identity. It then follows that
      # eigenvalues of P are exp(2πik/N) for k ∈ {0, ..., N-1}. Thus to specify
      # an eigenvalue it is sufficient to choose k. This is exactly the meaning
      # of the field sector.
      sector: <integer>
    - ...
  # (OPTIONAL) Specify global spin inversion symmetry.
  #
  # Set spin_inversion to 1 to indicate that the system is invariant upon
  # global spin inversion. Set it to -1 to indicate that a the wavefunction
  # changes sign. Leave this field out if your system does not have spin
  # inversion symmetry.
  spin_inversion: <integer>
# Description of the Hamiltonian.
hamiltonian:
  # Give your Hamiltonian a name.
  #
  # Example:
  #
  #   name: "Heisenberg Hamiltonian"
  name: <string>
  # A list of terms in the Hamiltonian. Full Hamiltonian is the sum of all terms.
  #
  # Each term specifies a particular type of interaction. Currently, 1-, 2-,
  # 3-, and 4-point interactions are supported. Which means that the
  # interaction is given by a 2ⁿ x 2ⁿ matrix where n is either 1, 2, 3, or 4.
  terms:
    # Defines the type of interaction.
    #
    # For example, the following specifies Heisenberg exchange interaction
    # σ₁σ₁ + σ₂σ₂ + σ₃σ₃:
    #
    #   - matrix: [[1,  0,  0,  0],
    #              [0, -1,  2,  0],
    #              [0,  2, -1,  0],
    #              [0,  0,  0,  1]]
    #
    # It is also possible to use complex numbers. Complex numbers are
    # represented by lists. I.e. to specify a + ib use [a, b].
    - matrix: <matrix-of-complex>
      # Specify to which sites the interaction should be applied. Depending on
      # the dimension of the matrix, it should be a list of either 1, 2, 3, or
      # 4 tuples.
      #
      # For example, the following specifies interaction between nearest
      # neighbours in a 4-spin chain:
      # 
      #   sites: [[0, 1], [1, 2], [2, 3], [3, 0]]
      sites: <list-of-list-of-integer>
# A list of observables.
#
# Each observable is a hermitian operator which is specified in the exact same
# way as the Hamiltonian. Expectation values of these operators will be
# evaluated on Hamiltonian eigenvectors after the diagonalization. Use it to
# compute various correlation functions or order parameters.
#
# If you do not wish to compute any observables except for energy, specify an empty list:
#
#   observables: []
observables: <list-of-operator>
# (OPTIONAL) Number of lowest-energy eigenvectors to compute. If not specified,
# only the ground state will be computed.
number_vectors: <integer>
# (OPTIONAL) Datatype to use for the computation. Possible values include
# 'float32', 'float64', 'complex64', and 'complex128'. If not specified,
# 'float64' will be used if your Hamiltonian is real, and 'complex128' if it's
# complex.
#
# Note that using 'float32' instead of 'float64' will not speed-up the
# matrix-vector products, but will reduce the memory usage.
datatype: <string>
# Specify the name of the output hdf5 file where the results should be saved.
#
# For example:
#
#  output: "data/heisenberg_chain_10.h5"
output: <string>
##########
## Advanced stuff (do not use unless you know what you're doing!)
##########
precision: <float>
max_primme_block_size: <integer>
max_primme_basis_size: <integer>