def print_orbital_weights_eigenstates_Gamma(subdir, prefix):
num_layers = 3
assert (num_layers == 3) # != 3 unimplemented
work = _get_work(subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(prefix))
E_F = fermi_from_scf(scf_path)
layer_orbitals = get_layer_orbitals(wout_path, num_layers)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(prefix))
Hr = extractHr(Hr_path)
Gamma_lat = np.array([0.0, 0.0, 0.0])
H_TB_Gamma = Hk_recip(Gamma_lat, Hr)
Es, U = np.linalg.eigh(H_TB_Gamma)
top = top_valence_indices(E_F, 2 * num_layers, Es)
eigenstate_weights = [
get_state_weights(layer_orbitals, U[:, [t]]) for t in top
]
print("eigenstate weights")
print(eigenstate_weights)
def print_orbital_weights_dm_K(subdir, prefix):
num_layers = 3
assert (num_layers == 3) # != 3 unimplemented
work = _get_work(subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(prefix))
E_F = fermi_from_scf(scf_path)
layer_orbitals = get_layer_orbitals(wout_path, num_layers)
Pzs = get_layer_projections(wout_path, num_layers)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(prefix))
Hr = extractHr(Hr_path)
K_lat = np.array([1 / 3, 1 / 3, 0.0])
H_TB_K = Hk_recip(K_lat, Hr)
Es, U = np.linalg.eigh(H_TB_K)
top = top_valence_indices(E_F, 2 * num_layers, Es)
layer_weights, layer_basis = get_layer_basis_from_dm_K(U, top, Pzs)
dm_basis_weights = [
get_state_weights(layer_orbitals, s) for s in layer_basis
]
print("dm basis weights")
print(dm_basis_weights)
def plot_orbital_weights_K(subdir, prefix):
num_layers = 3
assert (num_layers == 3) # != 3 unimplemented
work = _get_work(subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(prefix))
E_F = fermi_from_scf(scf_path)
layer_orbitals = get_layer_orbitals(wout_path, num_layers)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(prefix))
Hr = extractHr(Hr_path)
K_lat = np.array([1 / 3, 1 / 3, 0.0])
H_TB_K = Hk_recip(K_lat, Hr)
Es, U = np.linalg.eigh(H_TB_K)
top = top_valence_indices(E_F, 2 * num_layers, Es)
eigenstate_weights = [
get_state_weights(layer_orbitals, U[:, [t]]) for t in top
]
state_indices = [0, 0, 1, 1, 2, 2]
labels = [
r"$s_1$; $(+, \uparrow)$", r"$s_1$; $(-, \downarrow)$",
r"$s_2$; $(+, \uparrow)$", r"$s_2$; $(-, \downarrow)$",
r"$s_3$; $(+, \uparrow)$", r"$s_3$; $(-, \downarrow)$"
]
weight_keys = [
"(+, up)", "(-, down)", "(+, up)", "(-, down)", "(+, up)", "(-, down)"
]
syms = ["D", "D", "o", "o", "s", "s"]
colors = ["black", "red", "black", "red", "black", "red"]
vals = []
for state_index, label, key, sym, color in zip(state_indices, labels,
weight_keys, syms, colors):
vals.append([])
for layer_index in range(num_layers):
vals[-1].append(eigenstate_weights[state_index][key][layer_index])
plt.plot(range(num_layers),
vals[-1],
"k{}".format(sym),
markerfacecolor=(1, 1, 1, 0.0),
markeredgecolor=color,
label=label,
markersize=10)
plt.xlim(0 - 0.1, num_layers - 1 + 0.1)
plt.ylim(0, 1)
plt.legend(loc=0)
plt.savefig("{}_state_components.png".format(prefix),
bbox_inches='tight',
dpi=500)
def set_up_calculation(db, subdir, syms, AB_stacking, soc, vacuum_dist, D, xc,
pp):
# Choose separation between layers as if the system was a bulk system
# where all layers are the same as the first layer here.
# TODO -- is there a better strategy for this?
c_sep = get_c_sep(db, syms[0])
latvecs, at_syms, cartpos = make_cell(db, syms, c_sep, vacuum_dist,
AB_stacking)
system = Atoms(symbols=at_syms, positions=cartpos, cell=latvecs, pbc=True)
system.center(axis=2)
wann_valence, num_wann = get_wann_valence(system.get_chemical_symbols(),
soc)
num_bands = get_num_bands(num_wann)
holes_per_cell = None
qe_config = make_qe_config(system, D, holes_per_cell, soc, num_bands, xc,
pp)
prefix = make_prefix(syms)
work = _get_work(subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
if not os.path.exists(wannier_dir):
os.makedirs(wannier_dir)
bands_dir = os.path.join(work, "bands")
if not os.path.exists(bands_dir):
os.makedirs(bands_dir)
dirs = {'scf': wannier_dir, 'nscf': wannier_dir, 'bands': bands_dir}
qe_input = {}
for calc_type in ['scf', 'nscf', 'bands']:
qe_input[calc_type] = build_qe(system, prefix, calc_type, qe_config)
_write_qe_input(prefix, dirs[calc_type], qe_input, calc_type)
pw2wan_input = build_pw2wan(prefix, soc)
pw2wan_path = os.path.join(wannier_dir, "{}.pw2wan.in".format(prefix))
with open(pw2wan_path, 'w') as fp:
fp.write(pw2wan_input)
bands_post_input = build_bands(prefix)
bands_post_path = os.path.join(bands_dir,
"{}.bands_post.in".format(prefix))
with open(bands_post_path, 'w') as fp:
fp.write(bands_post_input)
wannier_input = Winfile(system, qe_config, wann_valence, num_wann)
win_path = os.path.join(wannier_dir, "{}.win".format(prefix))
with open(win_path, 'w') as fp:
fp.write(wannier_input)
return prefix
def _main():
np.set_printoptions(threshold=np.inf)
parser = argparse.ArgumentParser(
"TMD multilayer response to electric field",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix", type=str, help="Prefix for calculation")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument("--holes",
type=float,
default=8e12,
help="Hole concentration [cm^{-2}]")
parser.add_argument("--screened",
action='store_true',
help="Include screening by holes")
parser.add_argument(
"--diag_mass_only",
action='store_true',
help=
"Include q variation only through qx^2, qy^2 mass terms on diagonal")
args = parser.parse_args()
work = _get_work(args.subdir, args.prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
E_F_base = fermi_from_scf(scf_path)
d_A = 6.488 # Angstrom
d_bohr = _bohr_per_Angstrom * d_A
hole_density_cm2 = args.holes
hole_density_bohr2 = hole_density_cm2 / (10**8 * _bohr_per_Angstrom)**2
#print("hole_density_bohr2")
#print(hole_density_bohr2)
# Choose initial potential assuming holes are distributed uniformally.
sigma_layer_initial = (1 / 3) * _e_C * hole_density_bohr2
sigmas_initial = sigma_layer_initial * np.array([1.0, 1.0, 1.0])
#print("sigmas_initial [C/bohr^2]")
#print(sigmas_initial)
# Dielectric constant of WSe2:
# Kim et al., ACS Nano 9, 4527 (2015).
# http://pubs.acs.org/doi/abs/10.1021/acsnano.5b01114
#epsilon_r = 7.2
# Effective dielectric constant from DFT (LDA).
# avg(K^high_{top - bottom}, Gamma_{top - bottom})
epsilon_r = 7.87
H0_tot_Gamma, ps_tot_Gamma, mstar_inv_tot_Gamma = make_effective_Hamiltonian_Gamma(
args.subdir, args.prefix, top_two_only=False, verbose=False)
K_lat = np.array([1 / 3, 1 / 3, 0.0])
H0_tot_K, ps_tot_K, mstar_inv_tot_K = make_effective_Hamiltonian_K(
K_lat,
args.subdir,
args.prefix,
get_layer_basis_from_dm_K,
verbose=False)
Kp_lat = np.array([-1 / 3, -1 / 3, 0.0])
H0_tot_Kp, ps_tot_Kp, mstar_inv_tot_Kp = make_effective_Hamiltonian_K(
Kp_lat,
args.subdir,
args.prefix,
get_layer_basis_from_dm_K,
verbose=False)
H0s = [H0_tot_Gamma, H0_tot_K, H0_tot_Kp]
if args.diag_mass_only:
ps = [
np.zeros([6, 6], dtype=np.complex128),
np.zeros([6, 6], dtype=np.complex128),
np.zeros([6, 6], dtype=np.complex128)
]
def extract_diag(mstar_inv):
result = {}
for cp in range(2):
for c in range(2):
result[(cp, c)] = np.zeros([6, 6], dtype=np.complex128)
if c == cp:
for i in range(6):
result[(cp, c)][i, i] = mstar_inv[(cp, c)][i, i]
return result
mstar_invs = list(
map(extract_diag,
[mstar_inv_tot_Gamma, mstar_inv_tot_K, mstar_inv_tot_Kp]))
else:
ps = [ps_tot_Gamma, ps_tot_K, ps_tot_Kp]
mstar_invs = [mstar_inv_tot_Gamma, mstar_inv_tot_K, mstar_inv_tot_Kp]
Pzs = layer_projections()
E_V_nms = np.linspace(0.0, 1.2, 84)
if hole_density_cm2 > 0.0:
tol_abs = 1e-6 * sum(sigmas_initial)
else:
tol_abs = 1e-12 * _e_C
tol_rel = 1e-6
distr_args = []
for E_V_nm in E_V_nms:
distr_args.append([
E_V_nm, H0s, ps, mstar_invs, E_F_base, sigmas_initial, Pzs,
hole_density_bohr2, d_bohr, epsilon_r, tol_abs, tol_rel,
args.screened
])
with Pool() as p:
nh_Es = p.starmap(hole_distribution, distr_args)
plot_results(nh_Es, hole_density_bohr2, hole_density_cm2, epsilon_r,
args.screened, E_V_nms)
def _main():
parser = argparse.ArgumentParser(
"Plot band structure",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix", type=str, help="Prefix for calculation")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument(
"--num_layers",
type=int,
default=3,
help="Number of layers (required if group_layer_* options given)")
args = parser.parse_args()
if args.num_layers != 3:
raise ValueError("mirror check not implemented for num_layers != 3")
work = _get_work(args.subdir, args.prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
E_F = fermi_from_scf(scf_path)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(args.prefix))
Hr = extractHr(Hr_path)
K = np.array([1 / 3, 1 / 3, 0.0])
reduction_factor = 0.7
num_ks = 100
ks = vec_linspace(K, reduction_factor * K, num_ks)
xs = np.linspace(1, reduction_factor, num_ks)
basis = basis_state_labels(args.num_layers)
M = mirror_op()
# Assume SOC present and that model has 2*3 X(p) orbitals per layer
# and 2*5 M(d) in canonical Wannier90 order.
# Assumes atoms are ordered with all Xs first, then all Ms, and within
# M/X groups the atoms are in layer order.
orbitals_per_X = 6
orbitals_per_M = 10
# Base index for orbitals of each layer:
base_orbitals = [
args.num_layers * 2 * orbitals_per_X + z * orbitals_per_M
for z in range(args.num_layers)
]
# Orbitals contributing to j = +5/2 state:
x2y2_up = [base + 6 for base in base_orbitals]
xy_up = [base + 8 for base in base_orbitals]
x2y2_dn = [base + 7 for base in base_orbitals]
xy_dn = [base + 9 for base in base_orbitals]
num_top_bands = 2 * args.num_layers
weights = []
for i in range(num_top_bands):
weights.append([])
for k in ks:
Hk = Hk_recip(k, Hr)
Es, U = np.linalg.eigh(Hk)
top = top_valence_indices(E_F, num_top_bands, Es)
for i, band in enumerate(top):
total = 0
state = U[:, band]
mirror_eval = np.dot(state.conjugate().T, np.dot(M, state))[0, 0]
print("band {}; mirror <v|M|v> = {}".format(band, mirror_eval))
print("mirror deviation elements")
#Mdev = np.dot(M, state) - mirror_signs[i] * state
#for n, v in enumerate(Mdev):
# if abs(v)**2 > 1e-3:
# print(n, basis[n], v, abs(v)**2)
print("band, orb, orb_label, weight, evec comp")
#for n, v in enumerate(state):
# if abs(v)**2 > 1e-2:
# print(band, n, basis[n], abs(v)**2, v)
for n, v in enumerate(state):
print(band, n, basis[n], abs(v)**2, v)
for z, (n1_up, n2_up, n1_dn,
n2_dn) in enumerate(zip(x2y2_up, xy_up, x2y2_dn, xy_dn)):
# Appropriate arrangement for K.
# TODO - swap for -K.
# U[n, i] = <n|i> --> <i|n> = U[n, i].conjugate()
if z % 2 == 0:
evec_comp = (
1 / np.sqrt(2)) * (U[n1_dn, band].conjugate() -
1j * U[n2_dn, band].conjugate())
else:
evec_comp = (
1 / np.sqrt(2)) * (U[n1_up, band].conjugate() +
1j * U[n2_up, band].conjugate())
total += abs(evec_comp)**2
weights[i].append(1 - total)
for i, band_weights in enumerate(weights):
plt.plot(xs, band_weights, label="Band {}".format(i))
plt.legend(loc=0)
plt.xlabel("k / K", fontsize='large')
plt.ylabel("Weight outside l_z = +/- 2, up/down group")
plt.savefig("model_weights_K.png", bbox_inches='tight', dpi=500)
def _main():
parser = argparse.ArgumentParser(
"Plot band structure",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix", type=str, help="Prefix for calculation")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument("--DFT_only",
action='store_true',
help="Use DFT bands only (no Wannier)")
parser.add_argument("--fermi_shift",
action='store_true',
help="Shift plotted energies so that E_F = 0")
parser.add_argument("--band_extrema",
action='store_true',
help="Add lines at VBM/CBM")
parser.add_argument("--minE",
type=float,
default=None,
help="Minimum energy to plot")
parser.add_argument("--maxE",
type=float,
default=None,
help="Maximum energy to plot")
parser.add_argument("--plot_evecs",
action='store_true',
help="Plot eigenvector decomposition")
parser.add_argument(
"--num_layers",
type=int,
default=3,
help="Number of layers (required if group_layer_* options given)")
parser.add_argument(
"--group_layer_evecs_soc",
action='store_true',
help="Group eigenvectors weights by layer, assuming SOC")
parser.add_argument(
"--group_layer_evecs_no_soc",
action='store_true',
help="Group eigenvectors weights by layer, assuming no SOC")
parser.add_argument("--show",
action='store_true',
help="Show band plot instead of outputting file")
args = parser.parse_args()
work = _get_work(args.subdir, args.prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
E_F = fermi_from_scf(scf_path)
if args.minE is not None and args.maxE is not None:
if args.fermi_shift:
minE_plot = E_F + args.minE
maxE_plot = E_F + args.maxE
else:
minE_plot = args.minE
maxE_plot = args.maxE
else:
minE_plot, maxE_plot = None, None
alat = alat_from_scf(scf_path)
latVecs = latVecs_from_scf(scf_path)
if args.DFT_only:
Hr = None
else:
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(args.prefix))
Hr = extractHr(Hr_path)
bands_dir = os.path.join(work, "bands")
bands_path = os.path.join(bands_dir, "{}_bands.dat".format(args.prefix))
num_bands, num_ks, qe_bands = extractQEBands(bands_path)
outpath = args.prefix
if args.group_layer_evecs_soc:
orbitals_per_X = 6
orbitals_per_M = 10
comp_groups = make_comp_groups(orbitals_per_X, orbitals_per_M,
args.num_layers)
elif args.group_layer_evecs_no_soc:
orbitals_per_X = 3
orbitals_per_M = 5
comp_groups = make_comp_groups(orbitals_per_X, orbitals_per_M,
args.num_layers)
else:
comp_groups = None
plotBands(qe_bands,
Hr,
alat,
latVecs,
minE_plot,
maxE_plot,
outpath,
show=args.show,
symList=band_path_labels(),
fermi_energy=E_F,
plot_evecs=args.plot_evecs,
comp_groups=comp_groups,
fermi_shift=args.fermi_shift,
plot_band_extrema=args.band_extrema)
def _main():
np.set_printoptions(threshold=np.inf)
parser = argparse.ArgumentParser(
"Plot band structure",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix", type=str, help="Prefix for calculation")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument("--num_layers",
type=int,
default=3,
help="Number of layers")
args = parser.parse_args()
work = _get_work(args.subdir, args.prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(args.prefix))
E_F = fermi_from_scf(scf_path)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(args.prefix))
Hr = extractHr(Hr_path)
K = np.array([1 / 3, 1 / 3, 0.0])
reduction_factor = 0.7
num_ks = 100
ks = vec_linspace(K, reduction_factor * K, num_ks)
xs = np.linspace(1, reduction_factor, num_ks)
assert (Hr[(0, 0, 0)][0].shape[0] == get_total_orbitals(args.num_layers))
Pzs = get_layer_projections(wout_path, args.num_layers)
spin_operators = Pauli_over_full_basis(get_total_orbitals(args.num_layers))
num_top_bands = 2 * args.num_layers
deviations, proj_overlaps, spins = [], [], []
spins_non_layer_renormalized = []
for z in range(len(Pzs)):
deviations.append([])
proj_overlaps.append([])
spins.append([])
spins_non_layer_renormalized.append([])
for k in ks:
print("k = {}".format(k))
for z, Pz in enumerate(Pzs):
Hk = Hk_recip(k, Hr)
Es, U = np.linalg.eigh(Hk)
top = top_valence_indices(E_F, num_top_bands, Es)
print("top orbitals = ", top, "energies = ", [Es[t] for t in top])
proj_dms = [] # "dm" == density matrix
kz_spins = []
kz_spins_non_layer_renormalized = []
for restricted_index_n, band_n in enumerate(top):
state_n = U[:, [band_n]]
print("orbital", band_n)
for i, v in enumerate(state_n[:, 0]):
print(i, v)
dm_n = density_matrix([state_n], [1])
proj_dm = np.dot(Pz, np.dot(dm_n, Pz))
proj_dms.append(proj_dm)
kz_spins.append(expectation_normalized(proj_dm,
spin_operators))
kz_spins_non_layer_renormalized.append([
np.trace(np.dot(proj_dm, sigma))
for sigma in spin_operators
])
spins[z].append(kz_spins)
spins_non_layer_renormalized[z].append(
kz_spins_non_layer_renormalized)
proj_overlap = np.zeros([num_top_bands, num_top_bands],
dtype=np.complex128)
for restricted_index_np in range(len(top)):
for restricted_index_n in range(len(top)):
dm_np, dm_n = proj_dms[restricted_index_np], proj_dms[
restricted_index_n]
dm_np_norm = dm_np / np.trace(dm_np)
dm_n_norm = dm_n / np.trace(dm_n)
print(
"np, n, Tr rho_np^z, Tr rho_n^z, Tr rho_np^z rho_n^z",
restricted_index_np, restricted_index_n,
np.trace(dm_np), np.trace(dm_n),
np.trace(np.dot(dm_np, dm_n)))
proj_overlap[restricted_index_np,
restricted_index_n] = np.trace(
np.dot(dm_np_norm, dm_n_norm))
print("z = {}".format(z))
print("overlap = ")
print(proj_overlap)
# proj_overlap should be real.
eps_abs = 1e-12
assert (all([x.imag < eps_abs for x in np.nditer(proj_overlap)]))
# Compute deviation from desired 'all ones' value of proj_overlap.
deviation = sum([abs(1 - x) for x in np.nditer(proj_overlap)])
print("sum of abs(deviation) = {}".format(deviation))
proj_overlaps[z].append(proj_overlap)
deviations[z].append(deviation)
# Plot deviation from 1-band-per-layer representability.
for z in range(len(Pzs)):
plt.plot(xs, deviations[z], label="deviations for layer {}".format(z))
plt.legend(loc=0)
plt.savefig("{}_deviation_separability_K.png".format(args.prefix),
bbox_inches='tight',
dpi=500)
plt.clf()
# Plot layer-projected band overlaps.
for z in range(len(Pzs)):
for ip, i in [(0, 1), (1, 2), (0, 2)]:
ys = [v[ip, i].real for v in proj_overlaps[z]]
plt.plot(xs, ys, label="({}, {}) overlap".format(ip, i))
plt.legend(loc=0)
plt.savefig("{}_overlap_z_{}_separability_K.png".format(
args.prefix, z),
bbox_inches='tight',
dpi=500)
plt.clf()
# Plot layer-projected spin expectation values.
for z in range(len(Pzs)):
colors = ['k', 'g', 'b']
styles = ['-', '--', '.']
for band_n, style in zip([0, 1, 2], styles):
for (spin_index,
spin_dir), color in zip(enumerate(['x', 'y', 'z']), colors):
ys = [
spins[z][k][band_n][spin_index].real for k in range(num_ks)
]
plt.plot(xs,
ys,
'{}{}'.format(color, style),
label="Band {} spin {}".format(band_n, spin_dir))
plt.legend(loc=0)
plt.savefig("{}_z_{}_spin_real.png".format(args.prefix, z),
bbox_inches='tight',
dpi=500)
plt.clf()
for band_n, style in zip([0, 1, 2], styles):
for (spin_index,
spin_dir), color in zip(enumerate(['x', 'y', 'z']), colors):
ys = [
spins[z][k][band_n][spin_index].imag for k in range(num_ks)
]
plt.plot(xs,
ys,
'{}{}'.format(color, style),
label="Band {} spin {}".format(band_n, spin_dir))
plt.legend(loc=0)
plt.savefig("{}_z_{}_spin_imag.png".format(args.prefix, z),
bbox_inches='tight',
dpi=500)
plt.clf()
# Plot sum of spin expectation values over layers.
colors = ['k', 'g', 'b']
styles = ['-', '--', '.']
for (spin_index, spin_dir), color in zip(enumerate(['x', 'y', 'z']),
colors):
for band_n, style in zip([0, 1, 2], styles):
ys = np.zeros([num_ks], dtype=np.float64)
for z in range(len(Pzs)):
ys += np.array([
spins_non_layer_renormalized[z][k][band_n][spin_index].real
for k in range(num_ks)
])
plt.plot(xs,
ys,
'{}{}'.format(color, style),
label="Band {} spin {}".format(band_n, spin_dir))
plt.legend(loc=0)
plt.savefig("{}_z_total_spin_real.png".format(args.prefix),
bbox_inches='tight',
dpi=500)
plt.clf()
def _main():
parser = argparse.ArgumentParser(
"Plot band structure",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix", type=str, help="Prefix for calculation")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument(
"--num_layers",
type=int,
default=3,
help="Number of layers (required if group_layer_* options given)")
args = parser.parse_args()
if args.num_layers != 3:
raise ValueError("mirror check not implemented for num_layers != 3")
work = _get_work(args.subdir, args.prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
E_F = fermi_from_scf(scf_path)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(args.prefix))
Hr = extractHr(Hr_path)
Gamma = np.array([0.0, 0.0, 0.0])
K = np.array([1 / 3, 1 / 3, 0.0])
max_K_factor = 0.3
num_ks = 2
ks = vec_linspace(Gamma, max_K_factor * K, num_ks)
xs = np.linspace(0.0, max_K_factor, num_ks)
basis = basis_state_labels(args.num_layers)
M = mirror_op()
# Assume SOC present and that model has 2*3 X(p) orbitals per layer
# and 2*5 M(d) in canonical Wannier90 order.
# Assumes atoms are ordered with all Xs first, then all Ms, and within
# M/X groups the atoms are in layer order.
orbitals_per_X = 6
orbitals_per_M = 10
# Base index for orbitals of each layer:
X_base_orbitals = [
z * orbitals_per_X for z in range(1, 2 * args.num_layers - 1)
]
M_base_orbitals = [
args.num_layers * 2 * orbitals_per_X + z * orbitals_per_M
for z in range(args.num_layers)
]
pz_up = [n for n in X_base_orbitals]
pz_dn = [n + 1 for n in X_base_orbitals]
dz2_up = [n for n in M_base_orbitals]
dz2_dn = [n + 1 for n in M_base_orbitals]
#print(pz_up)
#print(pz_dn)
#print(dz2_up)
#print(dz2_dn)
orbital_group = list(itertools.chain(pz_up, pz_dn, dz2_up, dz2_dn))
num_top_bands = 2 * args.num_layers
weights = []
for i in range(num_top_bands):
weights.append([])
for k in ks:
print("k = ", k)
Hk = Hk_recip(k, Hr)
Es, U = np.linalg.eigh(Hk)
top = top_valence_indices(E_F, num_top_bands, Es)
print("top valence", top, [Es[t] for t in top])
mirror_signs = [1, 1, -1, -1, 1, 1]
for i, band in enumerate(top):
state = U[:, band]
mirror_eval = np.dot(state.conjugate().T, np.dot(M, state))[0, 0]
print("band {}; mirror <v|M|v> = {}".format(band, mirror_eval))
print("mirror deviation elements")
Mdev = np.dot(M, state) - mirror_signs[i] * state
for n, v in enumerate(Mdev):
if abs(v)**2 > 1e-3:
print(n, basis[n], v, abs(v)**2)
print("band, orb, orb_label, weight, evec comp")
#for n, v in enumerate(state):
# if abs(v)**2 > 1e-2:
# print(band, n, basis[n], abs(v)**2, v)
for n, v in enumerate(state):
print(band, n, basis[n], abs(v)**2, v)
total = 0
for n in orbital_group:
evec_comp = U[n, band].conjugate()
total += abs(evec_comp)**2
#print(total)
weights[i].append(1 - total)
#for i, band_weights in enumerate(weights):
# plt.plot(xs, band_weights, label="Band {}".format(i))
plt.plot(xs, weights[0], 'b.', label="Band 0")
plt.plot(xs, weights[1], 'g--', label="Band 1")
plt.legend(loc=0)
plt.xlabel("k / K", fontsize='large')
plt.ylabel("Weight outside inner p_z, dz^2")
plt.savefig("model_weights_Gamma.png", bbox_inches='tight', dpi=500)
def make_effective_Hamiltonian_Gamma(subdir,
prefix,
top_two_only,
verbose=False):
num_layers = 3
work = _get_work(subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(prefix))
E_F = fermi_from_scf(scf_path)
latVecs = latVecs_from_scf(scf_path)
alat_Bohr = 1.0
R = 2 * np.pi * np.linalg.inv(latVecs.T)
Gamma_cart = np.array([0.0, 0.0, 0.0])
K_lat = np.array([1 / 3, 1 / 3, 0.0])
K_cart = np.dot(K_lat, R)
if verbose:
print(K_cart)
print(latVecs)
upto_factor = 0.3
num_ks = 100
ks = vec_linspace(Gamma_cart, upto_factor * K_cart, num_ks)
xs = np.linspace(0.0, upto_factor, num_ks)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(prefix))
Hr = extractHr(Hr_path)
if top_two_only:
Pzs = [np.eye(get_total_orbitals(num_layers))]
else:
Pzs = get_layer_projections(wout_path, num_layers)
H_TB_Gamma = Hk(Gamma_cart, Hr, latVecs)
Es, U = np.linalg.eigh(H_TB_Gamma)
if top_two_only:
top = top_valence_indices(E_F, 2, Es)
else:
top = top_valence_indices(E_F, 2 * num_layers, Es)
layer_weights, layer_basis = get_layer_basis_Gamma(U, top, Pzs, verbose)
complement_basis_mat = nullspace(array_with_rows(layer_basis).conjugate())
complement_basis = []
for i in range(complement_basis_mat.shape[1]):
v = complement_basis_mat[:, [i]]
complement_basis.append(v / np.linalg.norm(v))
assert (len(layer_basis) + len(complement_basis) == 22 * num_layers)
for vl in [v.conjugate().T for v in layer_basis]:
for vc in complement_basis:
assert (abs(np.dot(vl, vc)[0, 0]) < 1e-12)
# 0th order effective Hamiltonian: H(Gamma) in layer basis.
H_layer_Gamma = layer_Hamiltonian_0th_order(H_TB_Gamma, layer_basis)
#E_repr = sum([Es[t] for t in top]) / len(top)
E_repr = Es[top[0]]
H_correction = correction_Hamiltonian_0th_order(Gamma_cart, Hr, latVecs,
E_repr, complement_basis,
layer_basis)
H0_tot = H_layer_Gamma + H_correction
H_PQ = correction_Hamiltonian_PQ(K_cart, Hr, latVecs, complement_basis,
layer_basis)
# Momentum expectation values <z_{lp}| dH/dk_{c}|_Gamma |z_l>
ps = layer_Hamiltonian_ps(Gamma_cart, Hr, latVecs, layer_basis)
ps_correction = correction_Hamiltonian_ps(Gamma_cart, Hr, latVecs, E_repr,
complement_basis, layer_basis)
ps_tot = deepcopy(ps)
for i, v in enumerate(ps_correction):
ps_tot[i] += v
# Inverse effective masses <z_{lp}| d^2H/dk_{cp}dk_{c}|_Gamma |z_l>
mstar_invs = layer_Hamiltonian_mstar_inverses(Gamma_cart, Hr, latVecs,
layer_basis)
mstar_invs_correction_base, mstar_invs_correction_other = correction_Hamiltonian_mstar_inverses(
Gamma_cart, Hr, latVecs, E_repr, complement_basis, layer_basis)
mstar_inv_tot = deepcopy(mstar_invs)
for mstar_contrib in [
mstar_invs_correction_base, mstar_invs_correction_other
]:
for k, v in mstar_contrib.items():
mstar_inv_tot[k] += v
if verbose:
print("H0")
print(H_layer_Gamma)
print("H_correction")
print(H_correction)
print("H_correction max")
print(abs(H_correction).max())
print("H_PQ max")
print(abs(H_PQ).max())
print("p")
print(ps)
print("ps max")
print(max([abs(x).max() for x in ps]))
print("ps correction")
print(ps_correction)
print("ps_correction max")
print(max([abs(x).max() for x in ps_correction]))
print("mstar_inv")
print(mstar_invs)
print("mstar_inv max")
print(max([abs(v).max() for k, v in mstar_invs.items()]))
print("mstar_inv_correction_base")
print(mstar_invs_correction_base)
print("mstar_inv_correction_base max")
print(
max([abs(v).max() for k, v in mstar_invs_correction_base.items()]))
print("mstar_inv_correction_other")
print(mstar_invs_correction_other)
print("mstar_inv_correction_other max")
print(
max([abs(v).max()
for k, v in mstar_invs_correction_other.items()]))
# Fit quality plots.
H_layers = []
for k in ks:
q = k - Gamma_cart
H_layers.append(
H_kdotp(q, H_layer_Gamma, H_correction, ps, ps_correction,
mstar_invs, mstar_invs_correction_base,
mstar_invs_correction_other))
Emks, Umks = [], []
for band_index in range(len(layer_basis)):
Emks.append([])
Umks.append([])
for k_index, Hk_layers in enumerate(H_layers):
Es_layers, U_layers = np.linalg.eigh(Hk_layers)
#print(k_index)
#print("U", U)
for band_index in range(len(layer_basis)):
Emks[band_index].append(Es_layers)
Umks[band_index].append(U_layers)
for band_index in range(len(layer_basis)):
plt.plot(xs, Emks[band_index])
TB_Emks = []
for m in range(len(top)):
TB_Emks.append([])
for k in ks:
this_H_TB_k = Hk(k, Hr, latVecs)
this_Es, this_U = np.linalg.eigh(this_H_TB_k)
for m, i in enumerate(top):
TB_Emks[m].append(this_Es[i])
for TB_Em in TB_Emks:
plt.plot(xs, TB_Em, 'k.')
plt.show()
# Effective masses.
print("effective mass, top valence band, TB model: m^*_{xx; yy; xy}")
print(
effective_mass_band(lambda k: Hk(k, Hr, latVecs), Gamma_cart,
top[0], alat_Bohr))
print(
"effective mass, top valence band, k dot p model: m^*_{xx; yy; xy}"
)
print(
effective_mass_band(
lambda k:
H_kdotp(k - Gamma_cart, H_layer_Gamma, H_correction, ps,
ps_correction, mstar_invs, mstar_invs_correction_base,
mstar_invs_correction_other), Gamma_cart,
len(layer_basis) - 1, alat_Bohr))
# Elements contributing to crossover scale.
t_Gamma_a = H0_tot[0, 2]
t_Gamma_b = H0_tot[0, 3]
print("t_Gamma_a, t_Gamma_b")
print(t_Gamma_a, t_Gamma_b)
print("norm(t_Gamma_a)")
print(abs(t_Gamma_a))
print("[t_Gamma]_{2, 4}, [t_Gamma]_{2, 5}")
print(H0_tot[2, 4], H0_tot[2, 5])
t_Gamma_direct = H0_tot[0, 4]
print("t_Gamma_direct, norm(t_Gamma_direct)")
print(t_Gamma_direct, abs(t_Gamma_direct))
print("E_SL_Gamma")
print([H0_tot[i, i] for i in range(6)])
print("H0_tot")
print(H0_tot)
Gamma_valence_max = Es[top[0]]
print("H0")
print_H0_LaTeX(H_layer_Gamma, Gamma_valence_max)
print("H0_tot")
print_H0_LaTeX(H0_tot, Gamma_valence_max)
dump_model_np("{}_model_Gamma".format(prefix), H0_tot, ps_tot,
mstar_inv_tot)
return H0_tot, ps_tot, mstar_inv_tot
def _main():
np.set_printoptions(threshold=np.inf)
parser = argparse.ArgumentParser(
"Plot band structure",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix", type=str, help="Prefix for calculation")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument("--num_layers",
type=int,
default=3,
help="Number of layers")
args = parser.parse_args()
work = _get_work(args.subdir, args.prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(args.prefix))
E_F = fermi_from_scf(scf_path)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(args.prefix))
Hr = extractHr(Hr_path)
Gamma = np.array([0.0, 0.0, 0.0])
K = np.array([1 / 3, 1 / 3, 0.0])
upto_factor = 0.3
num_ks = 100
ks = vec_linspace(Gamma, upto_factor * K, num_ks)
xs = np.linspace(0.0, upto_factor, num_ks)
assert (Hr[(0, 0, 0)][0].shape[0] == get_total_orbitals(args.num_layers))
Pzs = get_layer_projections(wout_path, args.num_layers)
num_top_bands = 2 * args.num_layers
for k in ks:
print("k = {}".format(k))
Hk = Hk_recip(k, Hr)
Es, U = np.linalg.eigh(Hk)
top = top_valence_indices(E_F, num_top_bands, Es)
print("top orbitals = ", top, "energies = ", [Es[t] for t in top])
tb_states = []
for restricted_index_n, band_n in enumerate(top):
state_n = U[:, [band_n]]
print("orbital", band_n)
for i, v in enumerate(state_n[:, 0]):
print(i, v)
tb_states.append(state_n)
dm = density_matrix(tb_states, [1] * len(tb_states))
for z, Pz in enumerate(Pzs):
print("z = {}".format(z))
proj_dm = np.dot(Pz, np.dot(dm, Pz))
proj_dm_evals, proj_dm_evecs = np.linalg.eigh(proj_dm)
print("proj_dm_evals")
print(proj_dm_evals)
print("proj_dm_evecs")
for i in range(proj_dm_evecs.shape[1]):
for j in range(proj_dm_evecs.shape[0]):
print(j, proj_dm_evecs[j, i])
def _main():
np.set_printoptions(threshold=np.inf)
parser = argparse.ArgumentParser(
"TMD multilayer response to electric field",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix", type=str, help="Prefix for calculation")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument("--num_layers",
type=int,
default=3,
help="Number of layers")
parser.add_argument("--holes",
type=float,
default=8e12,
help="Hole concentration [cm^{-2}]")
parser.add_argument("--screened",
action='store_true',
help="Include screening by holes")
parser.add_argument(
"--initial_mass",
action='store_true',
help=
"Use effective mass at E_perp = 0, p = 0 instead of recalculating for each phi"
)
parser.add_argument(
"--plot_initial",
action='store_true',
help=
"Plot initial band structure with max applied field, before charge convergence"
)
args = parser.parse_args()
if args.num_layers != 3:
assert ("num_layers != 3 not implemented")
work = _get_work(args.subdir, args.prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(args.prefix))
E_F_base = fermi_from_scf(scf_path)
latVecs = latVecs_from_scf(scf_path)
R = 2 * np.pi * np.linalg.inv(latVecs.T)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(args.prefix))
Hr = extractHr(Hr_path)
d_A = 6.488 # Angstrom
d_bohr = _bohr_per_Angstrom * d_A
hole_density_cm2 = args.holes
hole_density_bohr2 = hole_density_cm2 / (10**8 * _bohr_per_Angstrom)**2
#print("hole_density_bohr2")
#print(hole_density_bohr2)
# Choose initial potential assuming holes are distributed uniformally.
sigma_layer_initial = (1 / 3) * _e_C * hole_density_bohr2
sigmas_initial = sigma_layer_initial * np.array([1.0, 1.0, 1.0])
#print("sigmas_initial [C/bohr^2]")
#print(sigmas_initial)
# Dielectric constant of WSe2:
# Kim et al., ACS Nano 9, 4527 (2015).
# http://pubs.acs.org/doi/abs/10.1021/acsnano.5b01114
#epsilon_r = 7.2
# Effective dielectric constant from DFT (LDA).
# avg(K^high_{top - bottom}, Gamma_{top - bottom})
epsilon_r = 7.87
Pzs = get_layer_projections(wout_path, args.num_layers)
E_V_nms = np.linspace(0.0, 1.2, 84)
if args.plot_initial:
E_V_bohr = E_V_nms[-1] / (10 * _bohr_per_Angstrom)
phis_initial_max = get_phis(sigmas_initial, d_bohr, E_V_bohr,
epsilon_r, args.screened)
plot_H_k0_phis(H_k0s, phis_initial, Pzs, band_indices, E_F_base)
return
if hole_density_cm2 > 0.0:
tol_abs = 1e-6 * sum(sigmas_initial)
else:
tol_abs = 1e-12 * _e_C
tol_rel = 1e-6
distr_args = []
for E_V_nm in E_V_nms:
distr_args.append([
E_V_nm, R, Hr, latVecs, E_F_base, sigmas_initial, Pzs,
hole_density_bohr2, d_bohr, epsilon_r, tol_abs, tol_rel,
args.initial_mass, args.screened
])
with Pool() as p:
nh_Es = p.starmap(hole_distribution, distr_args)
plot_results(nh_Es, hole_density_bohr2, hole_density_cm2, epsilon_r,
args.screened, E_V_nms)
def _main():
parser = argparse.ArgumentParser(
"Plot band structure for multiple electric field values",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("prefix_E_0",
type=str,
help="Prefix for E = 0 calculation")
parser.add_argument("prefix_E_mid",
type=str,
help="Prefix for E != 0 calculation, middle value")
parser.add_argument("prefix_E_high",
type=str,
help="Prefix for E != 0 calculation, high value")
parser.add_argument(
"--subdir",
type=str,
default=None,
help="Subdirectory under work_base where calculation was run")
parser.add_argument(
"--minE",
type=float,
default=1.85,
help="Minimum energy to plot (using original energy zero)")
parser.add_argument(
"--maxE",
type=float,
default=5.75,
help="Maximum energy to plot (using original energy zero)")
parser.add_argument("--load",
action='store_true',
help="Load stored band data instead of recalculating")
args = parser.parse_args()
E_mid_val = args.prefix_E_mid.split('_')[-1]
E_high_val = args.prefix_E_high.split('_')[-1]
Gamma_lat = np.array([0.0, 0.0, 0.0])
M_lat = np.array([1 / 2, 0.0, 0.0])
K_lat = np.array([1 / 3, 1 / 3, 0.0])
band_path_lat = [Gamma_lat, M_lat, K_lat, Gamma_lat]
band_path_labels = ["$\\Gamma$", "$M$", "$K$", "$\\Gamma$"]
Nk_per_panel = 400
prefixes = [args.prefix_E_0, args.prefix_E_mid, args.prefix_E_high]
labels = [
"$E = 0$", "$E = {}$ V/nm".format(E_mid_val),
"$E = {}$ V/nm".format(E_high_val)
]
styles = ['r-', 'b-.', 'k--']
xs, special_xs, Emks = [], [], []
if args.load:
with open("Efield_bands.json", 'r') as fp:
in_data = json.load(fp)
xs, special_xs, Emks = list(
map(lambda k: [d[k] for d in in_data],
["xs", "special_xs", "Emks"]))
E_Gamma_Eperp_0 = in_data[0]["E_Gamma_Eperp_0"]
else:
out_data = []
for prefix_index, prefix in enumerate(prefixes):
work = _get_work(args.subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
latVecs = latVecs_from_scf(scf_path)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(prefix))
Hr = extractHr(Hr_path)
if prefix_index == 0:
E_F = fermi_from_scf(scf_path)
E_Gamma_Eperp_0 = get_E_Gamma(Hr, E_F)
this_xs, this_special_xs, this_Emks = calculate_bands(
Hr, latVecs, band_path_lat, Nk_per_panel)
this_Emks = shift_Emks(this_Emks, E_Gamma_Eperp_0)
xs.append(this_xs)
special_xs.append(this_special_xs)
Emks.append(this_Emks)
out_data.append({
"prefix": prefix,
"xs": this_xs,
"special_xs": this_special_xs,
"band_path_labels": band_path_labels,
"Emks": this_Emks,
"E_Gamma_Eperp_0": E_Gamma_Eperp_0
})
with open("Efield_bands.json", 'w') as fp:
json.dump(out_data, fp)
full_min_x, full_max_x = 0.0, 1.0
full_minE, full_maxE = args.minE - E_Gamma_Eperp_0, args.maxE - E_Gamma_Eperp_0
print("full_minE = ", full_minE)
print("full_maxE = ", full_maxE)
for this_xs, this_Emks, path_suffix in zip(xs, Emks,
["0.0", "0.5", "1.0"]):
out_path = "Efield_bands_E_{}.csv".format(path_suffix)
write_bands_csv(this_xs, this_Emks, out_path)
write_bands_aux(special_xs[0], band_path_labels, "Efield_bands_aux.csv")
plot_bands([xs[0], xs[-1]], special_xs[0], band_path_labels,
[Emks[0], Emks[-1]], [labels[0], labels[-1]],
[styles[0], styles[-1]], [full_min_x, full_max_x],
[full_minE, full_maxE], "full")
x_K = special_xs[0][2]
zoom_xlim = [x_K - 0.05, x_K + 0.05]
zoom_special_xs = [zoom_xlim[0], x_K, zoom_xlim[-1]]
zoom_band_path_labels = [
"$\\leftarrow M$", "$K$", "$\\rightarrow \\Gamma$"
]
zoom_ylim = [-0.3, 0.1]
print("zoom_xlim = ", zoom_xlim)
print("zoom_ylim = ", zoom_ylim)
plot_bands(xs, zoom_special_xs, zoom_band_path_labels, Emks, labels,
styles, zoom_xlim, zoom_ylim, "zoom")
def get_occupations(prefix, subdir, screened, d_bohr, hole_density_bohr2,
sigmas_initial, epsilon_r):
work = _get_work(subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(prefix))
E_F = fermi_from_scf(scf_path)
latVecs = latVecs_from_scf(scf_path)
alat_Bohr = 1.0
R = 2 * np.pi * np.linalg.inv(latVecs.T)
Gamma_cart = np.array([0.0, 0.0, 0.0])
K_lat = np.array([1 / 3, 1 / 3, 0.0])
K_cart = np.dot(K_lat, R)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(prefix))
Hr = extractHr(Hr_path)
H_TB_Gamma = Hk(Gamma_cart, Hr, latVecs)
Es_Gamma, U_Gamma = np.linalg.eigh(H_TB_Gamma)
H_TB_K = Hk(K_cart, Hr, latVecs)
Es_K, U_K = np.linalg.eigh(H_TB_K)
top_Gamma = top_valence_indices(E_F, 2, Es_Gamma)
top_K = top_valence_indices(E_F, 3, Es_Gamma)
assert (top_Gamma == [41, 40])
assert (top_K == [41, 40, 39])
E_top_Gamma, E_top_K = Es_Gamma[top_Gamma[0]], Es_K[top_K[0]]
Ediff = E_top_Gamma - E_top_K
def Hfn(k):
return Hk(k, Hr, latVecs)
mstar_top_Gamma = effective_mass_band(Hfn, Gamma_cart, top_Gamma[0],
alat_Bohr)
mstar_top_K = effective_mass_band(Hfn, K_cart, top_K[0], alat_Bohr)
mstar_Gamma = mstar_top_Gamma[0]
mstar_K = mstar_top_K[0]
num_layers = 3
Pzs = get_layer_projections(wout_path, num_layers)
if hole_density_bohr2 > 0.0:
tol_abs = 1e-6 * sum(sigmas_initial)
else:
tol_abs = 1e-12 * _e_C
tol_rel = 1e-6
nh_Gamma, nh_K, E_Gamma, E_K = hole_distribution(0.0,
R,
Hr,
latVecs,
E_F,
sigmas_initial,
Pzs,
hole_density_bohr2,
d_bohr,
epsilon_r,
tol_abs,
tol_rel,
screened=screened)
if hole_density_bohr2 > 0.0:
nh_Gamma_frac = nh_Gamma / hole_density_bohr2
nh_K_frac = nh_K / hole_density_bohr2
else:
nh_Gamma_frac = 0.0
nh_K_frac = 0.0
return Ediff, mstar_Gamma, mstar_K, nh_Gamma_frac, nh_K_frac, E_Gamma, E_K
def make_effective_Hamiltonian_K(k0_lat,
subdir,
prefix,
get_layer_basis,
verbose=False):
num_layers = 3
work = _get_work(subdir, prefix)
wannier_dir = os.path.join(work, "wannier")
scf_path = os.path.join(wannier_dir, "scf.out")
wout_path = os.path.join(wannier_dir, "{}.wout".format(prefix))
E_F = fermi_from_scf(scf_path)
latVecs = latVecs_from_scf(scf_path)
alat_Bohr = 1.0
R = 2 * np.pi * np.linalg.inv(latVecs.T)
K_cart = np.dot(k0_lat, R)
if verbose:
print(K_cart)
print(latVecs)
reduction_factor = 0.7
num_ks = 100
ks = vec_linspace(K_cart, reduction_factor * K_cart, num_ks)
xs = np.linspace(1, reduction_factor, num_ks)
Hr_path = os.path.join(wannier_dir, "{}_hr.dat".format(prefix))
Hr = extractHr(Hr_path)
Pzs = get_layer_projections(wout_path, num_layers)
H_TB_K = Hk(K_cart, Hr, latVecs)
Es, U = np.linalg.eigh(H_TB_K)
top = top_valence_indices(E_F, 2 * num_layers, Es)
layer_weights, layer_basis = get_layer_basis(U, top, Pzs, verbose)
complement_basis_mat = nullspace(array_with_rows(layer_basis).conjugate())
complement_basis = []
for i in range(complement_basis_mat.shape[1]):
v = complement_basis_mat[:, [i]]
complement_basis.append(v / np.linalg.norm(v))
assert (len(layer_basis) + len(complement_basis) == 22 * num_layers)
for vl in [v.conjugate().T for v in layer_basis]:
for vc in complement_basis:
assert (abs(np.dot(vl, vc)[0, 0]) < 1e-12)
# 0th order effective Hamiltonian: H(K) in layer basis.
H_layer_K = layer_Hamiltonian_0th_order(H_TB_K, layer_basis)
#E_repr = sum([Es[t] for t in top]) / len(top)
E_repr = Es[top[0]]
H_correction = correction_Hamiltonian_0th_order(K_cart, Hr, latVecs,
E_repr, complement_basis,
layer_basis)
H0_tot = H_layer_K + H_correction
H_PQ = correction_Hamiltonian_PQ(K_cart, Hr, latVecs, complement_basis,
layer_basis)
# Momentum expectation values <z_{lp}| dH/dk_{c}|_K |z_l>
ps = layer_Hamiltonian_ps(K_cart, Hr, latVecs, layer_basis)
ps_correction = correction_Hamiltonian_ps(K_cart, Hr, latVecs, E_repr,
complement_basis, layer_basis)
ps_tot = deepcopy(ps)
for i, v in enumerate(ps_correction):
ps_tot[i] += v
# Inverse effective masses <z_{lp}| d^2H/dk_{cp}dk_{c}|_K |z_l>
mstar_invs = layer_Hamiltonian_mstar_inverses(K_cart, Hr, latVecs,
layer_basis)
mstar_invs_correction_base, mstar_invs_correction_other = correction_Hamiltonian_mstar_inverses(
K_cart, Hr, latVecs, E_repr, complement_basis, layer_basis)
mstar_inv_tot = deepcopy(mstar_invs)
for mstar_contrib in [
mstar_invs_correction_base, mstar_invs_correction_other
]:
for k, v in mstar_contrib.items():
mstar_inv_tot[k] += v
if verbose:
print("H0")
print(H_layer_K)
print("H_correction")
print(H_correction)
print("H_correction max")
print(abs(H_correction).max())
print("H_PQ max")
print(abs(H_PQ).max())
print("ps")
print(ps)
print("ps max")
print(max([abs(x).max() for x in ps]))
print("ps correction")
print(ps_correction)
print("ps_correction max")
print(max([abs(x).max() for x in ps_correction]))
print("mstar_inv")
print(mstar_invs)
print("mstar_inv max")
print(max([abs(v).max() for k, v in mstar_invs.items()]))
print("mstar_inv_correction_base")
print(mstar_invs_correction_base)
print("mstar_inv_correction_base max")
print(
max([abs(v).max() for k, v in mstar_invs_correction_base.items()]))
print("mstar_inv_correction_other")
print(mstar_invs_correction_other)
print("mstar_inv_correction_other max")
print(
max([abs(v).max()
for k, v in mstar_invs_correction_other.items()]))
# Fit quality plots.
H_layers = []
for k in ks:
q = k - K_cart
H_layers.append(
H_kdotp(q, H_layer_K, H_correction, ps, ps_correction,
mstar_invs, mstar_invs_correction_base,
mstar_invs_correction_other))
Emks, Umks = [], []
for band_index in range(len(layer_basis)):
Emks.append([])
Umks.append([])
for k_index, Hk_layers in enumerate(H_layers):
Es, U = np.linalg.eigh(Hk_layers)
#print(k_index)
#print("U", U)
for band_index in range(len(layer_basis)):
Emks[band_index].append(Es)
Umks[band_index].append(U)
for band_index in range(len(layer_basis)):
plt.plot(xs, Emks[band_index])
TB_Emks = []
for m in range(len(top)):
TB_Emks.append([])
for k in ks:
this_H_TB_k = Hk(k, Hr, latVecs)
this_Es, this_U = np.linalg.eigh(this_H_TB_k)
for m, i in enumerate(top):
TB_Emks[m].append(this_Es[i])
for TB_Em in TB_Emks:
plt.plot(xs, TB_Em, 'k.')
plt.show()
plt.clf()
# Effective masses.
print(
"effective mass, top valence band, TB model: m^*_{xx; yy; xy} / m_e"
)
mstar_TB = effective_mass_band(lambda k: Hk(k, Hr, latVecs), K_cart,
top[0], alat_Bohr)
print(mstar_TB)
print(
"effective mass, top valence band, k dot p model: m^*_{xx; yy; xy} / m_e"
)
mstar_kdotp = effective_mass_band(
lambda k:
H_kdotp(k - K_cart, H_layer_K, H_correction, ps, ps_correction,
mstar_invs, mstar_invs_correction_base,
mstar_invs_correction_other), K_cart,
len(layer_basis) - 1, alat_Bohr)
print(mstar_kdotp)
# Elements contributing to crossover scale.
t_K = H0_tot[1, 2]
t_K_25 = H0_tot[2, 5]
Delta_K = H0_tot[1, 1] - H0_tot[2, 2]
lambda_SO = H0_tot[1, 1] - H0_tot[0, 0]
t_K_direct = H0_tot[1, 5]
print("t_K, Delta_K, lambda_SO")
print(t_K, Delta_K, lambda_SO)
print("t_K_25")
print(t_K_25)
print("norm(t_K), norm(t_K_25)")
print(abs(t_K), abs(t_K_25))
print("t_K_direct, norm(t_K_direct)")
print(t_K_direct, abs(t_K_direct))
print("E_SL_K top")
print([H0_tot[i, i] for i in [1, 3, 5]])
print("E_SL_K bottom")
print([H0_tot[i, i] for i in [0, 2, 4]])
# Elements contributing to effective dielectric constant.
print("Layer on-site energy differences:")
print(
"Top group of bands: middle layer - bottom layer; top layer - middle layer"
)
print(H0_tot[3, 3] - H0_tot[1, 1], H0_tot[5, 5] - H0_tot[3, 3])
print(
"Bottom group of bands: middle layer - bottom layer; top layer - middle layer"
)
print(H0_tot[2, 2] - H0_tot[0, 0], H0_tot[4, 4] - H0_tot[2, 2])
H_TB_Gamma = Hk_recip(np.array([0.0, 0.0, 0.0]), Hr)
Es_Gamma, U_Gamma = np.linalg.eigh(H_TB_Gamma)
Gamma_valence_max = Es_Gamma[top[0]]
print("H0")
print_H0_LaTeX(H_layer_K, Gamma_valence_max)
print("H0_tot")
print_H0_LaTeX(H0_tot, Gamma_valence_max)
dump_model_np("{}_model_K".format(prefix), H0_tot, ps_tot,
mstar_inv_tot)
phases = {(i, j): cmath.phase(H0_tot[i, j])
for i, j in [(0, 3), (1, 2), (2, 5), (3, 4)]}
phase_factors = list(
map(lambda x: np.exp(-1j * x), [
-phases[(0, 3)], -phases[(1, 2)], 0.0, 0.0, phases[(3, 4)],
phases[(2, 5)]
]))
phase_U = np.diag(phase_factors)
H0_tot_real_hop = np.dot(phase_U.conjugate().T,
np.dot(H0_tot, phase_U))
print("H0_tot_real_hop")
print_H0_LaTeX(H0_tot_real_hop, Gamma_valence_max)
return H0_tot, ps_tot, mstar_inv_tot