def honeycomb_ribbon(n=1,rtype="zigzag",stype="AB",has_spin=True,
t = 0.1,efield=0.1):
"""Return the hamiltonian of a ribbon"""
if rtype=="zigzag": g = geometry.honeycomb_zigzag_ribbon(n)
elif rtype=="armchair": g = geometry.honeycomb_zigzag_ribbon(n)
else: raise
if rtype=="amrchair": raise # not implemented yet
h = g.get_hamiltonian(has_spin=has_spin) # hamiltonian
if stype=="ABC": # trilayer ABC
h = build_honeycomb_trilayer(h,t,mvl=[0.,1.])
elif stype=="AB": # trilayer ABC
h = build_honeycomb_bilayer(h,t,mvl=[0.,1.])
add_electric_field(h,e=efield)
return h
def honeycomb_ribbon(n=1,rtype="zigzag",stype="AB",has_spin=True,
t = 0.1,efield=0.1):
"""Return the hamiltonian of a ribbon"""
if rtype=="zigzag": g = geometry.honeycomb_zigzag_ribbon(n)
elif rtype=="armchair": g = geometry.honeycomb_zigzag_ribbon(n)
else: raise
if rtype=="amrchair": raise # not implemented yet
h = g.get_hamiltonian(has_spin=has_spin) # hamiltonian
if stype=="ABC": # trilayer ABC
h = build_honeycomb_trilayer(h,t,mvl=[0.,1.])
elif stype=="AB": # trilayer ABC
h = build_honeycomb_bilayer(h,t,mvl=[0.,1.])
add_electric_field(h,e=efield)
return h
def get_zigzag_bilayer(n=10):
"""Get hamiltonian of a zigzag bilayer"""
import geometry
g = geometry.honeycomb_zigzag_ribbon(40)
drs = [np.array([0., 0., -1.]), np.array([0., 1., 1.])]
g = geometry.apilate(g, drs=drs)
h = g.get_hamiltonian()
return h
def get_zigzag_bilayer(n=10): """Get hamiltonian of a zigzag bilayer""" import geometry g = geometry.honeycomb_zigzag_ribbon(40) drs = [np.array([0.,0.,-1.]),np.array([0.,1.,1.])] g = geometry.apilate(g,drs=drs) h = g.get_hamiltonian() return h
def graphene_zigzag_ribbon(ntetramers=1,lambda_soc=0.0):
""" Creates teh hamiltonian for a graphene armchair ribbon"""
g = geometry.honeycomb_zigzag_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 generate_pentagon_island(nx,ny,pentagons=[0]):
"""Generate a Mullen island"""
g = geometry.honeycomb_zigzag_ribbon(ny)
g = g.supercell(2*nx+1)
g.dimensionality = 0
minx = np.min(g.x)
def finite(x,y):
if x<minx+.1: return False
return True
g = sculpt.intersec(g,finite)
g = sculpt.remove_unibonded(g)
g.center()
# now add the hexagon
dy = max(g.y) + 1.9
ym = max(g.y) # position of zigzag atoms
xz = [] # list of zigzag atoms
for ir in g.r: # loop over atoms
if (ir[1]-ym)<0.1: xz.append(ir[0]) # store upper zigzag atom
for ip in pentagons: # loop over pentagons
# generate positions
r1 = np.array([-1.+dx,0.+dy,0.])
r2 = np.array([1.+dx,0.+dy,0.])
r3 = np.array([.5+dx,np.sqrt(3.0)/2.+dy,0.])
r4 = np.array([-.5+dx,np.sqrt(3.0)/2.+dy,0.])
r5 = np.array([.5+dx,-np.sqrt(3.0)/2.+dy,0.])
r6 = np.array([-.5+dx,-np.sqrt(3.0)/2.+dy,0.])
# add the extra hexagons
g.r = [ri for ri in g.r] + [r1,r2,r3,r4,r5,r6]
g.r = [ri for ri in g.r] + [-r1,-r2,-r3,-r4,-r5,-r6]
#g.r = [r1,r2,r3,r4,r5,r6]
g.r = np.array(g.r)
g.r2xyz()
g.write()
h = g.get_hamiltonian() # initialize hamiltonian
def funh(ri,rj):
dr = ri-rj
if .1<dr.dot(dr)<1.3: return 1.0
else: return 0.0
h = hamiltonians.generate_parametric_hopping(h,funh)
return h
def generate_pentagon_island(nx, ny, pentagons=[0]):
"""Generate a Mullen island"""
g = geometry.honeycomb_zigzag_ribbon(ny)
g = g.supercell(2 * nx + 1)
g.dimensionality = 0
minx = np.min(g.x)
def finite(x, y):
if x < minx + .1: return False
return True
g = sculpt.intersec(g, finite)
g = sculpt.remove_unibonded(g)
g.center()
# now add the hexagon
dy = max(g.y) + 1.9
ym = max(g.y) # position of zigzag atoms
xz = [] # list of zigzag atoms
for ir in g.r: # loop over atoms
if (ir[1] - ym) < 0.1: xz.append(ir[0]) # store upper zigzag atom
for ip in pentagons: # loop over pentagons
# generate positions
r1 = np.array([-1. + dx, 0. + dy, 0.])
r2 = np.array([1. + dx, 0. + dy, 0.])
r3 = np.array([.5 + dx, np.sqrt(3.0) / 2. + dy, 0.])
r4 = np.array([-.5 + dx, np.sqrt(3.0) / 2. + dy, 0.])
r5 = np.array([.5 + dx, -np.sqrt(3.0) / 2. + dy, 0.])
r6 = np.array([-.5 + dx, -np.sqrt(3.0) / 2. + dy, 0.])
# add the extra hexagons
g.r = [ri for ri in g.r] + [r1, r2, r3, r4, r5, r6]
g.r = [ri for ri in g.r] + [-r1, -r2, -r3, -r4, -r5, -r6]
#g.r = [r1,r2,r3,r4,r5,r6]
g.r = np.array(g.r)
g.r2xyz()
g.write()
h = g.get_hamiltonian() # initialize hamiltonian
def funh(ri, rj):
dr = ri - rj
if .1 < dr.dot(dr) < 1.3: return 1.0
else: return 0.0
h = hamiltonians.generate_parametric_hopping(h, funh)
return h
def graphene_zigzag_ribbon(ntetramers=1, lambda_soc=0.0):
""" Creates teh hamiltonian for a graphene armchair ribbon"""
g = geometry.honeycomb_zigzag_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 generate_mullen_island(nx,ny,pristine=False):
"""Generate a Mullen island"""
g = geometry.honeycomb_zigzag_ribbon(ny)
g = g.supercell(2*nx+1+2)
g.dimensionality = 0
minx = np.min(g.x)
def finite(x,y):
if x<minx+.1: return False
return True
g = sculpt.intersec(g,finite)
g = sculpt.remove_unibonded(g)
g.center()
# now add the hexagon
dy = max(g.y) + 1.9
r1 = np.array([-1.,0.+dy,0.])
r2 = np.array([1.,0.+dy,0.])
r3 = np.array([.5,np.sqrt(3.0)/2.+dy,0.])
r4 = np.array([-.5,np.sqrt(3.0)/2.+dy,0.])
r5 = np.array([.5,-np.sqrt(3.0)/2.+dy,0.])
r6 = np.array([-.5,-np.sqrt(3.0)/2.+dy,0.])
if not pristine:
g.r = [ri for ri in g.r] + [r1,r2,r3,r4,r5,r6]
g.r = [ri for ri in g.r] + [-r1,-r2,-r3,-r4,-r5,-r6]
#g.r = [r1,r2,r3,r4,r5,r6]
g.r = np.array(g.r)
g.r2xyz()
g.write()
h = g.get_hamiltonian() # initialize hamiltonian
def funh(ri,rj):
dr = ri-rj
if .1<dr.dot(dr)<1.3: return 1.0
else: return 0.0
h = hamiltonians.generate_parametric_hopping(h,funh)
return h
def generate_mullen_island(nx, ny, pristine=False):
"""Generate a Mullen island"""
g = geometry.honeycomb_zigzag_ribbon(ny)
g = g.supercell(2 * nx + 1 + 2)
g.dimensionality = 0
minx = np.min(g.x)
def finite(x, y):
if x < minx + .1: return False
return True
g = sculpt.intersec(g, finite)
g = sculpt.remove_unibonded(g)
g.center()
# now add the hexagon
dy = max(g.y) + 1.9
r1 = np.array([-1., 0. + dy, 0.])
r2 = np.array([1., 0. + dy, 0.])
r3 = np.array([.5, np.sqrt(3.0) / 2. + dy, 0.])
r4 = np.array([-.5, np.sqrt(3.0) / 2. + dy, 0.])
r5 = np.array([.5, -np.sqrt(3.0) / 2. + dy, 0.])
r6 = np.array([-.5, -np.sqrt(3.0) / 2. + dy, 0.])
if not pristine:
g.r = [ri for ri in g.r] + [r1, r2, r3, r4, r5, r6]
g.r = [ri for ri in g.r] + [-r1, -r2, -r3, -r4, -r5, -r6]
#g.r = [r1,r2,r3,r4,r5,r6]
g.r = np.array(g.r)
g.r2xyz()
g.write()
h = g.get_hamiltonian() # initialize hamiltonian
def funh(ri, rj):
dr = ri - rj
if .1 < dr.dot(dr) < 1.3: return 1.0
else: return 0.0
h = hamiltonians.generate_parametric_hopping(h, funh)
return h
def generate_mullen_ribbon(nx,ny,single=False):
"""Generate a Mullen island"""
g = geometry.honeycomb_zigzag_ribbon(ny)
g = g.supercell(2*nx+2)
# now add the hexagon
dy = max(g.y) + 1.9
dx = np.sqrt(3.)/4 +0.
xx = np.array([dx,0.,0.])
g.r = [ri+xx for ri in g.r] # displace whole
r1 = np.array([-1.,0.+dy,0.])
r2 = np.array([1.,0.+dy,0.])
r3 = np.array([.5,np.sqrt(3.0)/2.+dy,0.])
r4 = np.array([-.5,np.sqrt(3.0)/2.+dy,0.])
r5 = np.array([.5,-np.sqrt(3.0)/2.+dy,0.])
r6 = np.array([-.5,-np.sqrt(3.0)/2.+dy,0.])
g.r = [ri for ri in g.r] + [r1,r2,r3,r4,r5,r6] # upper
if not single: g.r = [ri for ri in g.r] + [-r1,-r2,-r3,-r4,-r5,-r6] # lower
#g.r = [r1,r2,r3,r4,r5,r6]
g.r = np.array(g.r)
g.r2xyz()
g.write()
h = g.get_hamiltonian() # initialize hamiltonian
def funh(ri,rj):
dr = ri-rj
if .1<dr.dot(dr)<1.3: return 1.0
else: return 0.0
h = hamiltonians.generate_parametric_hopping(h,funh)
return h
def generate_mullen_ribbon(nx, ny, single=False):
"""Generate a Mullen island"""
g = geometry.honeycomb_zigzag_ribbon(ny)
g = g.supercell(2 * nx + 2)
# now add the hexagon
dy = max(g.y) + 1.9
dx = np.sqrt(3.) / 4 + 0.
xx = np.array([dx, 0., 0.])
g.r = [ri + xx for ri in g.r] # displace whole
r1 = np.array([-1., 0. + dy, 0.])
r2 = np.array([1., 0. + dy, 0.])
r3 = np.array([.5, np.sqrt(3.0) / 2. + dy, 0.])
r4 = np.array([-.5, np.sqrt(3.0) / 2. + dy, 0.])
r5 = np.array([.5, -np.sqrt(3.0) / 2. + dy, 0.])
r6 = np.array([-.5, -np.sqrt(3.0) / 2. + dy, 0.])
g.r = [ri for ri in g.r] + [r1, r2, r3, r4, r5, r6] # upper
if not single:
g.r = [ri for ri in g.r] + [-r1, -r2, -r3, -r4, -r5, -r6] # lower
#g.r = [r1,r2,r3,r4,r5,r6]
g.r = np.array(g.r)
g.r2xyz()
g.write()
h = g.get_hamiltonian() # initialize hamiltonian
def funh(ri, rj):
dr = ri - rj
if .1 < dr.dot(dr) < 1.3: return 1.0
else: return 0.0
h = hamiltonians.generate_parametric_hopping(h, funh)
return h
import geometry # library to create crystal geometries
import hamiltonians # library to work with hamiltonians
import input_tb90 as in90
import heterostructures
import multilayers
import os
import numpy as np
g = geometry.honeycomb_zigzag_ribbon(ntetramers=4)
#g = geometry.square_ribbon(1)
#g.supercell(2)
h = hamiltonians.hamiltonian(g)
#h.get_simple_tb()
h.get_simple_tb(mag_field=0.1)
h.add_zeeman([0.02, 0.0, 0.])
#h.add_kane_mele(0.1)
if False:
h.write(output_file="hamiltonian_0.in")
os.system("cp tb90.in-scf tb90.in")
os.system("tb90.x")
#in90.tb90in().write()
if False:
h.read("hamiltonian.in")
mag = in90.read_magnetization() # ground state magnetism
h.align_magnetism(mag)
h.write()
os.system("cp tb90.in-bands tb90.in")
os.system("tb90.x")
import geometry # library to create crystal geometries
import hamiltonians # library to work with hamiltonians
import heterostructures
import numpy as np
import klist
import pylab as py
import green
import interactions
g = geometry.square_ribbon(4) # create geometry of the system
g = geometry.honeycomb_zigzag_ribbon(1) # create geometry of the system
h = g.get_hamiltonian() # create hamiltonian
hr = h.copy()
hl = h.copy()
es = np.linspace(-3., 3., 100) # array with the energies
hlist = [h for i in range(10)] # create a list with the hamiltonians
# of the scattering centrl part
# create a junction object
ht = heterostructures.create_leads_and_central_list(hr, hl, hlist)
ht.block2full()
# calculate transmission
figt = ht.plot_landauer(energy=es, delta=0.00001,
has_eh=h.has_eh) # figure with the transmission
figb = h.plot_bands(nkpoints=300) # figure with the bands
py.show()
#import pyximport; pyximport.install() import chi # library for response calculation import geometry import hamiltonians import interactions import numpy as np import pylab as py U = 1.0 # hubbard strength g = geometry.chain() g = geometry.honeycomb_zigzag_ribbon(1) h = g.get_hamiltonian() ############# SCF ab = interactions.hubbard(h,U=U) # create operators mf = interactions.antiferro_initialization(h,value=0.1) # create operators #mf = interactions.selfconsistency(h,ab_list=ab,old_mf=mf) # SCF cycle mf = interactions.tb90_scf(h,ab,mf) # SCF cycle #exit() ############## h.intra += mf # add mean field h.get_bands() #exit() #ms = chi.chi1d(h,energies=energies,q=0.1,U=U,adaptive=True,delta=delta,nk=100) #exit() #h.plot_bands()
# zigzag ribbon
import sys
sys.path.append("../../../pygra") # add pygra library
import geometry
g = geometry.honeycomb_zigzag_ribbon(10) # create geometry of a zigzag ribbon
h = g.get_hamiltonian() # create hamiltonian of the system
h.add_rashba(0.2) # add Rashba spin orbit coupling
h.add_zeeman([0., 0., 0.2]) # add off-plane Zeeman coupling
h.get_bands(nkpoints=300) # calculate band structure
import geometry # library to create crystal geometries
import hamiltonians # library to work with hamiltonians
import input_tb90 as in90
import heterostructures
import multilayers
import os
g = geometry.honeycomb_zigzag_ribbon(ntetramers=1)
h = hamiltonians.hamiltonian(g)
h.get_simple_tb()
h.add_zeeman([0.1,0.0,0.0])
#h.add_kane_mele(0.1)
if False:
h.write(output_file = "hamiltonian_0.in")
os.system("cp tb90.in-scf tb90.in")
os.system("tb90.x")
#in90.tb90in().write()
if False:
h.read("hamiltonian.in")
mag = in90.read_magnetization() # ground state magnetism
h.align_magnetism(mag)
h.write()
os.system("cp tb90.in-bands tb90.in")
os.system("tb90.x")
if False:
import geometry # library to create crystal geometries
import hamiltonians # library to work with hamiltonians
import heterostructures
import numpy as np
import klist
import pylab as py
import green
import interactions
g = geometry.square_ribbon(4) # create geometry of the system
g = geometry.honeycomb_zigzag_ribbon(1) # create geometry of the system
h = g.get_hamiltonian() # create hamiltonian
hr = h.copy()
hl = h.copy()
es = np.linspace(-3.,3.,100) # array with the energies
hlist = [h for i in range(10)] # create a list with the hamiltonians
# of the scattering centrl part
# create a junction object
ht = heterostructures.create_leads_and_central_list(hr,hl,hlist)
ht.block2full()
# calculate transmission
figt = ht.plot_landauer(energy=es,delta=0.00001,has_eh=h.has_eh) # figure with the transmission
figb = h.plot_bands(nkpoints=300) # figure with the bands
py.show()
