Dear Anton,
I am a bit confused now, if the determinant of G matrix is always zero, how
inverse of G matrix is calculated to find Hall conductance and longitudinal
one in the link I have mentioned in the first email? All leads have the
same chemical potential there too.
Best regards,
Ali
Best regards
On Wed, Feb 15, 2017 at 9:59 PM, Anton Akhmerov wrote: Dear Ali, The determinant of G matrix is always zero, since if you apply the
same voltage to all leads, no current should flow. I am unsure why it
is only zero for some energies for you. Best,
Anton On Wed, Feb 15, 2017 at 7:56 PM, Ali Asgharpour
Thanks. By the way, I want to find voltage difference in a system but,
for
some Fermi energies, the determinant of G matrix is zero and obviously I
have a singular matrix error. Is there any way not to encounter this
error
except adding "if statements"? Best regards, Ali On Wed, Feb 15, 2017 at 8:02 PM, Anton Akhmerov
Hi Ali, We subtract the sums because that is the definition of the conductance
matrix. However this complete function really should be written as
kwant.smatrix(syst, args=[p]).conductance_matrix() (see also the
documentation of the conductance_matrix from Kwant). Best,
Anton On Wed, Feb 15, 2017 at 3:43 PM, Ali Asgharpour
Hello all, I have a question about one of the functions in this link: w3_pump_QHE/Laughlinargument.ipynb For plotting Hall conductance and longitudinal one, there is a section
where
you defined a G function, which I put it below: def G(syst, p):
smatrix = kwant.smatrix(syst, args=[p])
G = [[smatrix.transmission(i, j) for i in range(num_leads)] for j in range(num_leads)]
G -= np.diag(np.sum(G, axis=0))
return calculate_sigmas(G) I want to know why we need this line " G -= np.diag(np.sum(G,
axis=0)) "
since G matrix is already calculated in the previous line? Your time and consideration are greatly appreciated. Best regards, Ali