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""" DOS and DC conductivity of the Haldane model | |
Lattice : Honeycomb lattice; | |
Disorder : Disorder class Uniform at different sublattices; | |
Configuration : size of the system 256x256, with domain decomposition (nx=ny=12), periodic boundary conditions, | |
double precision, automatic scaling; | |
Calculation : DOS and conductivity_dc; | |
Modification : magnetic field is off; | |
""" | |
import kite | |
import pybinding as pb | |
from math import sqrt | |
def haldane(): | |
"""Return the lattice specification for Haldane model""" | |
a = 0.24595 # [nm] unit cell length | |
a_cc = 0.142 # [nm] carbon-carbon distance | |
t=-1 | |
t2 = t/10 | |
m=0 | |
# create a lattice with 2 primitive vectors | |
lat = pb.Lattice( | |
a1=[a, 0], | |
a2=[a/2, a/2 * sqrt(3)] | |
) | |
lat.add_sublattices( | |
# name and position | |
('A', [0, -a_cc/2],-m), | |
('B', [0, a_cc/2],m) | |
) | |
lat.add_hoppings( | |
# inside the main cell | |
([0, 0], 'A', 'B', t), | |
# between neighboring cells | |
([1, -1], 'A', 'B', t), | |
([0, -1], 'A', 'B', t), | |
([1, 0], 'A', 'A', t2 * 1j), | |
([0, -1], 'A', 'A', t2 * 1j), | |
([-1, 1], 'A', 'A', t2 * 1j), | |
([1, 0], 'B', 'B', t2 * -1j), | |
([0, -1], 'B', 'B', t2 * -1j), | |
([-1, 1], 'B', 'B', t2 * -1j) | |
) | |
return lat | |
# make a haldane lattice | |
lattice = haldane() | |
# add Uniformly distributed disorder | |
disorder = kite.Disorder(lattice) | |
disorder.add_disorder('A', 'Uniform', +0.0, 0.6) | |
disorder.add_disorder('B', 'Uniform', +0.0, 0.6) | |
# number of decomposition parts in each direction of matrix. | |
# This divides the lattice into various sections, each of which is calculated in parallel | |
nx = ny = 2 | |
# number of unit cells in each direction. | |
lx = ly = 256 | |
# make config object which caries info about | |
# - the number of decomposition parts [nx, ny], | |
# - lengths of structure [lx, ly] | |
# - boundary conditions, setting True as periodic boundary conditions, and False elsewise, | |
# - info if the exported hopping and onsite data should be complex, | |
# - info of the precision of the exported hopping and onsite data, 0 - float, 1 - double, and 2 - long double. | |
# - scaling, if None it's automatic, if present select spectrum_bound=[e_min, e_max] | |
configuration = kite.Configuration(divisions=[nx, ny], length=[lx, ly], boundaries=[True, True], | |
is_complex=True, precision=0) | |
calculation = kite.Calculation(configuration) | |
# require the calculation of DOS and conductivity_dc | |
calculation.dos(num_points=1000, num_moments=512, num_random=10, num_disorder=1) | |
calculation.conductivity_dc(num_points=1000, num_moments=256, num_random=50, num_disorder=1, | |
direction='xy', temperature=100) | |
# configure the *.h5 file | |
kite.config_system(lattice, configuration, calculation, filename='haldane.h5', | |
disorder=disorder) |
Author
quantum-kite
commented
Jun 9, 2018
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