def main():
g = get_geometry(pi/2)
file_name = 'thermo_4probe_spectral.h5'
# Load data from a file, if it exists
solver = u.CurrentSolver.resume(file_name, g)
solver.set_solvers(kin_solver=u.KIN_SOLVER_BLOCK,
sp_solver=u.SP_SOLVER_TWPBVP)
# Solve and save spectral quantities to a file.
# This takes some time, so we'll want to avoid redoing it unnecessarily.
#
# calculage_G=True instructs the solver also to calculate a spectral
# conductance matrix for the circuit, which can be used to conveniently
# evaluate currents given distribution functions in the terminals.
#
solver.solve_spectral_and_save_if_needed(file_name, calculate_G=True)
# Solve thermovoltage vs. temperature
dT = 0.001
# ... and write results to a text file
output = open('thermo_4probe.dat', 'w')
print >> output, "%% %14s %14s" % ("T (E_T)", "dV/dT (ueV/K)")
for T in logspace(log10(dT + 1e-4), log10(20), 100):
# Compute the thermovoltage:
g.t_mu = 0
g.t_t = T
g.t_t[2] += dT/2
g.t_t[3] -= dT/2
# Make the terminals 2, 3 to float
# Currents entering them flow in wires 2, 3
def zero_currents():
Ic, Ie = solver.get_currents_from_G(w_jT=[2,3], w_jL=[])
return [Ic[2], Ic[3]]
def set_potentials(z):
g.t_mu[2], g.t_mu[3] = z
u.optimize_parameters_for([0,0], zero_currents, set_potentials)
# Print the thermovoltage at terminal 2 in ueV/K
print >> output, " %14g %14g" % (T, g.t_mu[2] / dT * 86.17343)
def main():
g = get_geometry(pi/2)
file_name = 'nonlocal_thermovoltage_spectral.h5'
# It is possible to do a self-consistent iteration, but this is quite
# slow.
#
# Change False to True below, if you want to try that:
do_selfconsistent_iteration = False
# Load data from a file, if it exists
solver = u.CurrentSolver.resume(file_name, g, ne=200, chunksize=50)
solver.set_solvers(kin_solver=u.KIN_SOLVER_BLOCK,
sp_solver=u.SP_SOLVER_TWPBVP)
# Solve and save spectral quantities to a file.
# This takes some time, so we'll want to avoid redoing it unnecessarily.
#
# calculage_G=True instructs the solver also to calculate a spectral
# conductance matrix for the circuit, which can be used to conveniently
# evaluate currents given distribution functions in the terminals.
#
if not do_selfconsistent_iteration:
solver.solve_spectral_and_save_if_needed(file_name, calculate_G=True)
# Solve thermovoltage vs. temperature
dT = 0.05
# ... and write results to a text file
output = open('nonlocal_thermovoltage.dat', 'w')
print >> output, "%% %14s %14s" % ("T (E_T)", "dV/dT (ueV/K)")
if do_selfconsistent_iteration:
Ts = logspace(log10(dT + 1e-4), log10(10), 15)[1:]
else:
Ts = logspace(log10(dT + 1e-4), log10(10), 100)
for T in Ts:
# (Optional) self-consistent iteration
if do_selfconsistent_iteration:
g.t_mu = 0
g.t_t = T
it = u.self_consistent_matsubara_iteration(g, max_ne=50)
#it = u.self_consistent_realtime_iteration(solver)
for k, d, I_error in it:
print >> sys.stderr, "%% Self-consistent iteration %d (residual %g)" % (k, d.residual_norm())
if (d.residual_norm() < 1e-3 * 100 and I_error < 1e-5):
break
else:
raise RuntimeError("Self-cons. iteration didn't converge!")
solver.solve_spectral()
solver.calculate_G()
solver.save("nonlocal_thermovoltage_T_%.2f.h5" % T)
# Compute the thermovoltage:
g.t_mu = 0
g.t_t = T
g.t_t[11] += dT
# Make the terminals 0, 3, 4, 5, 11 to float
# Currents entering them flow in wires 0, 3, 4, 5, 7
def zero_currents():
Ic, Ie = solver.get_currents_from_G(w_jT=[0,3,4,5,7], w_jL=[])
#Ic, Ie = solver.get_currents(w_jT=[0,3,4,5,7], w_jL=[], ix=0)
return [Ic[0], Ic[3], Ic[4], Ic[5], Ic[7]]
def set_potentials(z):
g.t_mu[0], g.t_mu[3], g.t_mu[4], g.t_mu[5], g.t_mu[11] = z
u.optimize_parameters_for([0,0,0,0,0], zero_currents, set_potentials)
# Print the thermovoltage at terminal 4 in ueV/K
print >> output, " %14g %14g" % (T, g.t_mu[4] / dT * 86.17343)
# Solve the kinetic equations for some temperature and a larger
# temperature difference, and dump the result for inspection.
g.t_t = 1e-4
g.t_t[11] = 8
solver.solve_kinetic()
solver.save('dump.h5')
output.close()