Dear Zhang Bing,

Please take a look at the following bit of code that calculates nonlocal resistance in a 4-terminal device from a Kwant scattering matrix. (Taken from the Kwant example to appear with the revised version of Kwant paper.)

# First we calculate the conductance matrix given the scattering matrix S. cond = np.array([[s.transmission(i, j) for j in xrange(n)] for i in xrange(n)]) # Correct the reflection blocks, so that rows and columns sum to zero. cond -= np.diag(cond.sum(axis=0))

# In order to calculate the nonlocal conductance we eliminate one row and # one column from the condutcance matrix. This amounts to setting the # corresponding voltage to zero and using current conservation to calculate # the current through the last terminal. cm = conductance_matrix(sys, energy, [args])[:-1, :-1] # We then set the current to be 1 in the lead 0, -1 in lead 2, and # calculate the voltage in lead 1 (so V_1 - V_3 since V_3 = 0). nonlocal_resistance = np.linalg.solve(cm, [1, 0, -1])[1]

Generalization to a 6-terminal case should be straightforward.

Best regards, Anton Akhmerov

On Sat, Apr 26, 2014 at 6:14 AM, ZHANG Bing bzhangac@ust.hk wrote:

Dear Sir,

I am a PhD student of Hong Kong University of Science and Technology. I want to use KWANT to caculate Hall resistance of a Hall bar structure.We can get the conductance between 6 electrodes, but how to get hall resistance? Can you give me some help? Thank you very much.

Best Regards, Zhang Bing