def gb_vs_iters_disp(sigma_0,iters,strength):
"""
Calculate Gilbert Damping versus number of iterations for displacement regime.
"""
with open('result_disp_'+str(strength)+'_'+str(iters)+'.txt', 'w') as f:
system = topological_insulator.make_topo_displacement(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,strength)
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,sys)
for num in range(2,iters+2):
system = topological_insulator.make_topo_displacement(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,strength)
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,sys)) / 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_disp_'+str(strength)+'_'+str(iters)+'.png')
plt.close(fig)
return gb
def build_fm_topo(): """ Build a topological insulator with a ferromagnetic island. """ sigma_0 = 1.e-4+1.e-4j topo = 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) topo_sys = topo[0] topo_sys.update_hamil_2(calc.build_fm_island(calc.make_hamil_layers(topo_sys.hamil, 20, topo[1],20),np.radians(0),0,0.02+0.j,20,20),20,20) x_list = [] y_list = [] for theta in range(0,180,18): theta_rad = np.radians(theta) gb = calc.find_gb(theta_rad,0,topo_sys) x_list.append(theta) y_list.append(gb) 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()
