def gb_vs_iters(sigma_0, iters,strength):
"""
Plot Gilbert Damping as a function of iterations to test convergence.
"""
with open('result_'+str(strength)+'_'+str(iters)+'.txt', 'w') as f:
system = topological_insulator.make_topo(50.+0.j, 3.645+0.j, -68.6+0.j, -0.1+0.j, -51.2+0.j, -0.05+0.j, -0.067+0.j, 1.+0.j,sigma_0,0.5,500,20,1)
sys = system[0]
sys.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(sys.hamil, 20, system[1],20),np.radians(0),0,0.02+0.j,20,20),20,20)
x_list = []
y_list = []
gb = calc.find_gb(0,0,randomize_hamil(sys,strength))
for num in range(2,iters+2):
system = topological_insulator.make_topo(50.+0.j, 3.645+0.j, -68.6+0.j, -0.1+0.j, -51.2+0.j, -0.05+0.j, -0.067+0.j, 1.+0.j,sigma_0,0.5,500,20,1)
sys = system[0]
sys.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(sys.hamil, 20, system[1],20),np.radians(0),0,0.02+0.j,20,20),20,20)
x_list.append(num)
gb = (gb*(num-1) + calc.find_gb(0,0,randomize_hamil(sys,strength))) / num
y_list.append(gb)
f.write(str(gb) + '\n')
fig = plt.figure()
ax = fig.add_axes([0.1, 0.1, 0.8, 0.8])
ax.plot(x_list,y_list,color='g')
fig.savefig('output_'+str(strength)+'_'+str(iters)+'.png')
plt.close(fig)
return gb
def test_gb_greens(): sigma_0 = 1.e-4+1.e-4j topo = topological_insulator.make_topo(50.+0.j, 3.645+0.j, -68.6+0.j, -0.1+0.j, -51.2+0.j, -0.05+0.j, -0.067+0.j, 1.+0.j,sigma_0,0.5,500,20,1) system = topo[0] system.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(system.hamil, 20, topo[1],20),0,0,0.02+0.j,20,20,padding=False),20,20) gb_1 = find_gb_theta_phi(0,0,system) system.greens_ret = mod_greens(system,1e-6) gb_2 = find_gb_theta_phi(0,0,system) return gb
def test_gb(): energy_low = -0.11 energy_high = -0.07 efermi = -0.09 sigma_0 = 1.e-4+1.e-4j temp = 0.01 topo = topological_insulator.make_topo(50.+0.j, 3.645+0.j, -68.6+0.j, -0.1+0.j, -51.2+0.j, -0.01+0.j, 2.+0.j, 1.+0.j,sigma_0,0.5,500,20,1) system = topo[0] system.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(system.hamil, 20, topo[1],20),0,0,0.02+0.j,20,20),20,20) x_list = [] y_list = [] for omega in [1e-2]: x_list.append(omega) y_list.append(find_gb_omega(omega,energy_low,energy_high,system,efermi,temp, 0.02)) fig = plt.figure() ax = fig.add_axes([0.1, 0.1, 0.8, 0.8]) ax.plot(x_list,y_list,color='g') plt.show()
def test_gb_greens_local_2(): sigma_0 = 1.e-4+1.e-4j topo = topological_insulator.make_topo(50.+0.j, 3.645+0.j, -68.6+0.j, -0.1+0.j, -51.2+0.j, -0.05+0.j, -0.067+0.j, 1.+0.j,sigma_0,0.5,500,20,1) system = topo[0] system.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(system.hamil, 20, topo[1],20),0,0,0.02+0.j,20,20,padding=False),20,20) system.greens_ret = mod_greens(system,1e-3) gb = find_gb_local(0,0,system) xs = [] ys_1 = [] ys_2 = [] s = 0 for i in range(gb[0].shape[0]): xs.append(i) ys_1.append(gb[0][i]) ys_2.append(gb[2][i]) s+=gb[0][i] plt.plot(xs,ys_1) plt.show()
def gb_versus_temp():
sigma_0 = 1.e-4+1.e-4j
for energy in range(-80,-50):
with open('gbvstemp_result_'+str(energy/1000)+'.txt', 'w') as f:
xs = []
ys = []
energy = energy / 1000
for temp in range(10,410,20):
xs.append(temp)
topo = topological_insulator.make_topo(50.+0.j, 3.645+0.j, -68.6+0.j, -0.1+0.j, -51.2+0.j, -0.05+0.j, energy, 1.+0.j,sigma_0,0.5,500,20,1)
system = topo[0]
system.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(system.hamil, 20, topo[1],20),0,0,0.01+0.j,20,20,padding=False),20,20)
system.greens_ret = mod_greens(system,5e-3,magmom=100,boson_dist=boson_dist(0.01,temp))
gb = find_gb_local(0,0,system)
s = 0
for i in range(gb[0].shape[0]):
s+=gb[0][i]
ys.append(s)
f.write(str(energy)+' '+str(temp)+' '+str(s))
plt.plot(xs,ys)
plt.savefig('gb_vs_temp_' + str(energy)+'.png')
plt.close()
def test_gb_greens_local():
sigma_0 = 1.e-4+1.e-4j
layers = 50
sites = 20
topo = topological_insulator.make_topo(50.+0.j, 3.645+0.j, -68.6+0.j, -0.1+0.j, -51.2+0.j, -0.05+0.j, -0.067+0.j, 1.+0.j,sigma_0,0.5,500,sites,1)
system = topo[0]
system.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(system.hamil, layers, topo[1],sites),0,0,0.01+0.j,sites,layers,padding=False),sites,layers)
system.greens_ret = mod_greens(system,1e-2,magmom=100)
gb = find_gb_local(0,0,system,fm_width=layers)
maj = gb[1]
grid = maj.reshape((layers,sites))
fig, ax = plt.subplots()
cax = ax.imshow(grid, extent=(0, sites, 0, layers), interpolation='spline16', cmap=cm.OrRd)
cbar = fig.colorbar(cax)
#cbar.ax.set_yticklabels(['< -1', '0', '> 1'])
fig.savefig('majority'+str(sites)+'x'+str(layers)+'.png')
plt.close(fig)
mino = gb[2]
grid = mino.reshape((layers,sites))
fig, ax = plt.subplots()
cax = ax.imshow(grid, extent=(0, sites, 0, layers), interpolation='spline16', cmap=cm.OrRd)
cbar = fig.colorbar(cax)
#cbar.ax.set_yticklabels(['< -1', '0', '> 1'])
fig.savefig('minority'+str(sites)+'x'+str(layers)+'.png')
plt.close(fig)
#return gb
gil = gb[0]
s = 0
for i in range(gil.shape[0]):
s+=gil[i]
grid = gil.reshape((layers,sites))
fig, ax = plt.subplots()
cax = ax.imshow(grid, extent=(0, sites, 0, layers), interpolation='spline16', cmap=cm.OrRd)
cbar = fig.colorbar(cax)
#cbar.ax.set_yticklabels(['< -1', '0', '> 1'])
fig.savefig('gilbert'+str(sites)+'x'+str(layers)+'.png')
plt.close(fig)
