pyspinw_testall.py

""" Antiferromagnetic chain example """

from multiprocessing.spawn import freeze_support

from pyspinw.coupling import HeisenbergCoupling
from pyspinw.hamiltonian import Hamiltonian
from pyspinw.interface import (generate_exchanges, filter, axis_anisotropies, generate_structure,
                               generate_helical_structure)
from pyspinw.path import Path, Path1D
from pyspinw.site import LatticeSite
from pyspinw.sample import Powder
from pyspinw.symmetry.supercell import TrivialSupercell, SummationSupercell, CommensuratePropagationVector
from pyspinw.symmetry.unitcell import UnitCell
from pyspinw.structures import Structure
from pyspinw.legacy.genmagstr import genmagstr
from math import sqrt
import sys

from pyspinw.debug_plot import debug_plot
import matplotlib.pyplot as plt

if __name__ == "__main__":
    """Reproduces Tutorial 2: https://spinw.org/tutorials/02tutorial"""
    freeze_support()

    ########################################
    # Parameters for all examples
    use_rust = "py" not in sys.argv[1] if len(sys.argv) > 1 else True
    use_rotating = False
    ########################################

    unit_cell = UnitCell(3, 8, 8)
    sites = generate_helical_structure(unit_cell, positions=[[0,0,0]], moments=[[0,1,0]],
                                       perpendicular=[0,0,1], propagation_vector=[0.5, 0, 0], names=["MCu1"])
    exchanges = generate_exchanges(sites=sites,
                                   max_distance=3.1,
                                   coupling_type=HeisenbergCoupling,
                                   j=1)
    hamiltonian = Hamiltonian(sites, exchanges)
    hamiltonian.print_summary()
    path = Path([[0,0,0], [1,0,0]])
    hamiltonian.spaghetti_plot(path, scale='log', show=False, use_rust=use_rust, use_rotating=use_rotating)

    """ Antiferromagnetic chain example with applied magnetic field """
    unit_cell = UnitCell(4,6,6)
    sites = generate_structure(unit_cell, positions=[[0,0,0], [0.5,0,0]], moments=[[0,0,1], [0,0,-1]], names=['X', 'Y'])
    exchanges = generate_exchanges(sites=sites,
                                   bond=1,
                                   coupling_type=HeisenbergCoupling,
                                   j=1,
                                   direction_filter=filter([1,0,0], symmetric=True))
    anisotropies = axis_anisotropies(sites, -0.1)

    hamiltonian = Hamiltonian(sites, exchanges, anisotropies)

    hamiltonian.print_summary()

    path = Path([[0,0,0], [2,0,0]])
    hamiltonian.spaghetti_plot(path, field=[0,0,7], show=False, use_rust=use_rust)

    """ Ferromagnetic chain example """
    unit_cell = UnitCell(1,1,1)
    only_site = LatticeSite(0, 0, 0, 0,0,1, name="X")
    s = Structure([only_site], unit_cell=unit_cell)
    exchanges = generate_exchanges(sites=[only_site],
                                   unit_cell=unit_cell,
                                   max_distance=1.1,
                                   coupling_type=HeisenbergCoupling,
                                   j=-1,
                                   direction_filter=filter([1,0,0]))
    hamiltonian = Hamiltonian(s, exchanges)
    path = Path([[0,0,0], [1,0,0]])
    hamiltonian.spaghetti_plot(path, show=False, use_rust=use_rust)

    """ Kagome Antiferromagnet example """
    unit_cell = UnitCell(6, 6, 10, gamma=120)
    s = generate_structure(unit_cell, positions=[[0.5,0,0], [0,0.5,0], [0.5,0.5,0]], moments=[[1,2,0], [-2,-1,0], [1,-1,0]],
                           names=['X','Y','Z'], magnitudes=[1,1,1], moments_unit='lu')
    j1 = generate_exchanges(sites=s, bond=1, j=1)
    j2 = generate_exchanges(sites=s, bond=2, j=0.11)
    exchanges = j1 + j2
    hamiltonian = Hamiltonian(s, exchanges)
    hamiltonian.print_summary()
    path = Path([[-0.5,0,0], [0,0,0], [0.5,0.5,0]])
    hamiltonian.spaghetti_plot(path, show=False, use_rust=use_rust)

    """ Kagome Ferromagnet example """
    unit_cell = UnitCell(6,6,5, gamma=120)
    x = LatticeSite(0.5, 0, 0, 0, 1, 0, name="X")
    y = LatticeSite(0, 0.5, 0, 0, 1, 0, name="Y")
    z = LatticeSite(0.5, 0.5, 0, 0, 1, 0, name="Z")
    sites = [x, y, z]
    s = Structure(sites, unit_cell=unit_cell, supercell=TrivialSupercell(scaling=(1,1,1)))
    exchanges = generate_exchanges(sites=[x, y, z],
                                   unit_cell=unit_cell,
                                   max_distance=4.,
                                   coupling_type=HeisenbergCoupling,
                                   j=-1)
    hamiltonian = Hamiltonian(s, exchanges)
    hamiltonian.print_summary()
    path = Path([[-0.5,0,0], [0,0,0], [0.5,0.5,0]])
    hamiltonian.energy_plot(path, show=False, use_rust=use_rust)
    #sample = Powder(hamiltonian)
    #path1D = Path1D(0.1, 2.5, n_points=100)
    #sample.show_spectrum(path1D, n_energy_bins=250)

    """ Kagome 3x3 Antiferromagnet example """
    unit_cell = UnitCell(6, 6, 40, gamma=120)
    s = generate_helical_structure(unit_cell, positions=[[0.5,0,0], [0,0.5,0], [0.5,0.5,0]],
                                   moments=[[0,1,0], [0,1,0], [-1,-1,0]], magnitudes=[1,1,1], names=['X', 'Y', 'Z'],
                                   moments_unit='lu', perpendicular=[0,0,1], propagation_vector=[-1./3., -1./3., 0])
    exchanges = generate_exchanges(sites=s,
                                   bond=1,
                                   coupling_type=HeisenbergCoupling,
                                   j=1)
    hamiltonian = Hamiltonian(s, exchanges)
    hamiltonian.print_summary()
    #from pyspinw.gui.viewer import show_hamiltonian
    #show_hamiltonian(hamiltonian)
    path = Path([[-0.5,0,0], [0,0,0], [0.5,0.5,0]])
    fig = hamiltonian.spaghetti_plot(path, show=False, use_rust=use_rust, use_rotating=use_rotating)
    fig.axes[0].set_ylim(0, 3)
    fig.axes[1].set_ylim(0, 1)
    #plt.show()

    """ Square-lattice Antiferromagnet example """
    unit_cell = UnitCell(3, 3, 9)
    sites = [LatticeSite(0, 0, 0, 1, 0, 0, name="X")]
    k = CommensuratePropagationVector(0.5, 0.5, 0)
    s = Structure(sites, unit_cell, supercell=SummationSupercell(propagation_vectors=[k]))
    j1 = generate_exchanges(sites, unit_cell, min_distance=0, max_distance=3.1, coupling_type=HeisenbergCoupling, j=59.65)
    j2 = generate_exchanges(sites, unit_cell, min_distance=4, max_distance=4.3, coupling_type=HeisenbergCoupling, j=-3.75)
    j3 = generate_exchanges(sites, unit_cell, min_distance=5, max_distance=6.1, coupling_type=HeisenbergCoupling, j=1)
    exchanges = j1 + j2 + j3
    hamiltonian = Hamiltonian(s, exchanges)
    hamiltonian.print_summary()
    path = Path([[3/4, 1/4, 0], [1/2, 1/2, 0], [1/2, 0, 0], [3/4, 1/4, 0], [1, 0, 0], [1/2, 0, 0]], n_points_per_segment=51)
    fig = hamiltonian.spaghetti_plot(path, show=False, use_rust=use_rust)
    fig.axes[0].set_ylim(0, 300)
    fig.axes[1].set_ylim(0, 5)
    #plt.show()

    """ Triangular Antiferromagnet example """
    unit_cell = UnitCell(3, 3, 4, gamma=120)
    sites = generate_helical_structure(unit_cell, positions=[[0,0,0]], moments=[[0,1,0]], magnitudes=[3./2], names=['X'],
                                       perpendicular=[0,0,1], propagation_vector=[1./3., 1./3., 0])
    exchanges = generate_exchanges(sites=sites,
                                   bond=1,
                                   coupling_type=HeisenbergCoupling,
                                   j=1)
    anisotropies = axis_anisotropies(sites, 0.2)
    hamiltonian = Hamiltonian(sites, exchanges, anisotropies)
    hamiltonian.print_summary()
    path = Path([[0,0,0], [1,1,0]], n_points_per_segment=401)
    fig = hamiltonian.spaghetti_plot(path, show=False, use_rust=use_rust, use_rotating=use_rotating)
    fig.axes[0].set_ylim(0, 4)
    fig.axes[1].set_ylim(0, 3)
    #plt.show()

    """ Triangular Antiferromagnet example """
    unit_cell = UnitCell(3, 3, 8, gamma=120)
    sites = generate_helical_structure(unit_cell, positions=[[0, 0, 0], [0, 0, 0.5]], moments=[[0, 1, 0], [0, 1, 0]],
                magnitudes=[3./2, 3./2], propagation_vector=[1./3, 1./3, 0], perpendicular=[0, 0, 1])
    exchanges = generate_exchanges(sites=sites, bond=1, coupling_type=HeisenbergCoupling, j=1) \
              + generate_exchanges(sites=sites, bond=2, coupling_type=HeisenbergCoupling, j=-0.1)
    anisotropies = axis_anisotropies(sites, 0.2)
    hamiltonian = Hamiltonian(sites, exchanges, anisotropies)
    hamiltonian.print_summary()
    path = Path([[0,0,0], [1,1,0]], n_points_per_segment=401)
    fig = hamiltonian.spaghetti_plot(path, show=False, use_rust=use_rust, use_rotating=use_rotating)
    fig.axes[0].set_ylim(0, 7)
    fig.axes[1].set_ylim(0, 5)

    plt.show()