def add_frustrated_antiferromagnetism(h,m):
"""Add frustrated magnetism"""
import geometry
if h.geometry.sublattice_number==3:
g = geometry.kagome_lattice()
elif h.geometry.sublattice_number==4:
g = geometry.pyrochlore_lattice()
import films
g = films.geometry_film(g,nz=1)
else: raise # not implemented
ms = []
for i in range(len(h.geometry.r)): # loop
ii = h.geometry.sublattice[i] # index of the sublattice
if callable(m):
ms.append(-g.r[int(ii)]*m(h.geometry.r[i])) # save this one
else:
ms.append(-g.r[int(ii)]*m) # save this one
h.add_magnetism(ms) # add the magnetization
def get_geometry_film():
""" Create a 0d island"""
lattice_name = getbox("lattice") # get the option
# lattice_name = builder.get_object("lattice").get_active_text()
if lattice_name == "Cubic":
geometry_builder = geometry.cubic_lattice
elif lattice_name == "Diamond":
geometry_builder = geometry.diamond_lattice_minimal
elif lattice_name == "Pyrochlore":
geometry_builder = geometry.pyrochlore_lattice
else:
raise
g = geometry_builder() # call the geometry
import films
g = films.geometry_film(g, int(get("thickness")))
# g = g.supercell(nsuper)
g.real2fractional()
g.fractional2real()
g.center()
return g
def buckled_honeycomb_lattice():
"""Return a buckled honeycomb lattice"""
import films
g = diamond_lattice_minimal()
g = films.geometry_film(g, nz=1)
return g
def tetrahedral_lattice():
"""Return a single layer of the pyrochlore lattice"""
g = pyrochlore_lattice()
import films
g = films.geometry_film(g, nz=1)
return g
from pygra importgeometry import topology import klist import classicalspin import films import ribbon import islands g = geometry.honeycomb_lattice() # generate the geometry g = geometry.triangular_lattice() # generate the geometry g = geometry.pyrochlore_lattice() # generate the geometry #g = geometry.kagome_lattice() # geenrate the geometry #g = geometry.diamond_lattice_minimal() # generate the geometry g = films.geometry_film(g,nz=2) #g = g.remove(len(g.r)-1) #g = ribbon.bulk2ribbon(g,n=10) g = g.supercell(2) #g = islands.get_geometry(name="triangular",n=3) #g.dimensionality = 0 #g.write() #g.write() #g = geometry.kagome_lattice() # geenrate the geometry #g = g.supercell(2) sm = classicalspin.SpinModel(g) # generate a spin model sm.add_heisenberg() # add heisenber exchange #sm.add_field([0.,0.,1.5]) sm.minimize_energy() # minimize Hamiltonian #exit() h = g.get_hamiltonian() # get the Hamiltonian
import sys
import os
sys.path.append("../../../pygra") # add the pygra library
import geometry
import numpy as np
import hybrid
import films
import operators
g = geometry.diamond_lattice_minimal(
) # get the three dimensional diamond lattice
g = films.geometry_film(g, nz=20) # create a film
h = g.get_hamiltonian(is_multicell=True) # create hamiltonian
def get_hamiltonian():
"""Hamiltonian for parameter p"""
h = g.get_hamiltonian(is_multicell=True,
is_sparse=False) # create hamiltonian
def step(z, width=0.00001):
"""This will yield 0 for z<0 and 1 for z>0"""
out = (-np.tanh(z / width) + 1.0) / 2. # this is the interpolator
return out
h.add_antiferromagnetism(lambda r: 0.7 * step(r[2]), axis=[0., 0., 1.])
h.shift_fermi(lambda r: 1. * (-step(r[2], width=0.0001) + 1.0))
h.add_swave(lambda r: 0.4 * (-step(r[2]) + 1.0))
h.add_kane_mele(0.05)
return h
