def get_armchair_bilayer(n=10):
"""Get hamiltonian of an armchair bilayer"""
import geometry
g = geometry.honeycomb_armchair_ribbon(30)
drs = [np.array([0., 0., -1.]), np.array([np.sqrt(3.) / 2., 0., 1.])]
g = geometry.apilate(g, drs=drs)
h = g.get_hamiltonian()
return h
def get_armchair_bilayer(n=10): """Get hamiltonian of an armchair bilayer""" import geometry g = geometry.honeycomb_armchair_ribbon(30) drs = [np.array([0.,0.,-1.]),np.array([np.sqrt(3.)/2.,0.,1.])] g = geometry.apilate(g,drs=drs) h = g.get_hamiltonian() return h
def graphene_armchair_ribbon(ntetramers=1,lambda_soc=0.0):
""" Creates teh hamiltonian for a graphene armchair ribbon"""
g = geometry.honeycomb_armchair_ribbon(ntetramers) # create the geometry
h = hamiltonians.hamiltonian(g) # create the hamiltonian
# get the intracell and intercell terms
(intra,inter) = hamiltonians.kane_mele(g.x,g.y,
celldis=g.celldis,lambda_soc=lambda_soc)
h.intra = intra # assign intracell
h.inter = inter # assign intercell
return h # return hamiltonian
def graphene_armchair_ribbon(ntetramers=1, lambda_soc=0.0):
""" Creates teh hamiltonian for a graphene armchair ribbon"""
g = geometry.honeycomb_armchair_ribbon(ntetramers) # create the geometry
h = hamiltonians.hamiltonian(g) # create the hamiltonian
# get the intracell and intercell terms
(intra, inter) = hamiltonians.kane_mele(g.x,
g.y,
celldis=g.celldis,
lambda_soc=lambda_soc)
h.intra = intra # assign intracell
h.inter = inter # assign intercell
return h # return hamiltonian
# file
file_eigen = "eigen_heff.dat"
os.remove(file_eigen)
with open(file_eigen, "a") as myfile:
myfile.write("# Swave Real Imag")
neig = 2 # number of eigenvalues
fig_mu = py.figure()
fig_mu.set_facecolor("white")
sfig_mu = fig_mu.add_subplot(111)
svalues = np.arange(0.0, 0.5, 0.02)
for sval in svalues:
# g = geometry.honeycomb_armchair_ribbon(ntetramers=15)
g = geometry.honeycomb_armchair_ribbon(ntetramers=25)
# create hamiltonians heterojunction
h_right = hamiltonians.hamiltonian(g)
h_left = hamiltonians.hamiltonian(g)
# central is QSH
h_right.get_simple_tb()
h_left.get_simple_tb()
h_left.read(input_file="hamiltonian_canted_25.in")
# shift fermi energy
mu = 0.04
h_right.shift_fermi(0.4)
h_left.shift_fermi(mu)
# zigzag ribbon
import sys
sys.path.append("../../../pygra") # add pygra library
import geometry
g = geometry.honeycomb_armchair_ribbon(
60) # create geometry of a zigzag ribbon
h = g.get_hamiltonian(has_spin=True) # create hamiltonian of the system
h.add_haldane(.1) # add Haldane coupling
h.get_bands() # calculate band structure
#h.get_bands(operator=h.get_operator("valley"))