> From: anton.akhmerov@gmail.com
> Date: Fri, 26 Jun 2015 00:42:29 +0200
> Subject: Re: [Kwant] Spin
> To: alexis-bozio@hotmail.fr
> CC: kwant-discuss@kwant-project.org
>
> So this means your Kwant installation is broken.
>
> What is the OS?
> How did you install Kwant?
> What does
>
> import kwant; kwant.test()
>
> return?
>
> Best,
> Anton
>
> On Thu, Jun 25, 2015 at 1:34 PM, Alexis Bozio <alexis-bozio@hotmail.fr> wrote:
> > Hi Anton,
> > Thank you for awnsering! I don't think that it is e problem with my code
> > because there because i am using the one that is used on the tutoring of
> > kwant:
> >
> > import kwant
> >
> > # For plotting
> > from matplotlib import pyplot
> >
> > # For matrix support
> > import tinyarray
> >
> > # define Pauli-matrices for convenience
> > sigma_0 = tinyarray.array([[1, 0], [0, 1]])
> > sigma_x = tinyarray.array([[0, 1], [1, 0]])
> > sigma_y = tinyarray.array([[0, -1j], [1j, 0]])
> > sigma_z = tinyarray.array([[1, 0], [0, -1]])
> >
> >
> > def make_system(a=1, t=1.0, alpha=0.5, e_z=0.08, W=10, L=30):
> > # Start with an empty tight-binding system and a single square lattice.
> > # `a` is the lattice constant (by default set to 1 for simplicity).
> > lat = kwant.lattice.square(a)
> >
> > sys = kwant.Builder()
> >
> > #### Define the scattering region. ####
> > sys[(lat(x, y) for x in range(L) for y in range(W))] = \
> > 4 * t * sigma_0 + e_z * sigma_z
> > # hoppings in x-direction
> > sys[kwant.builder.HoppingKind((1, 0), lat, lat)] = \
> > -t * sigma_0 - 1j * alpha * sigma_y
> > # hoppings in y-directions
> > sys[kwant.builder.HoppingKind((0, 1), lat, lat)] = \
> > -t * sigma_0 + 1j * alpha * sigma_x
> >
> > #### Define the left lead. ####
> > lead = kwant.Builder(kwant.TranslationalSymmetry((-a, 0)))
> >
> > lead[(lat(0, j) for j in xrange(W))] = 4 * t * sigma_0 + e_z * sigma_z
> > # hoppings in x-direction
> > lead[kwant.builder.HoppingKind((1, 0), lat, lat)] = \
> > -t * sigma_0 - 1j * alpha * sigma_y
> > # hoppings in y-directions
> > lead[kwant.builder.HoppingKind((0, 1), lat, lat)] = \
> > -t * sigma_0 + 1j * alpha * sigma_x
> >
> > #### Attach the leads and return the finalized system. ####
> > sys.attach_lead(lead)
> > sys.attach_lead(lead.reversed())
> >
> > return sys
> >
> >
> > def plot_conductance(sys, energies):
> > # Compute conductance
> > data = []
> > for energy in energies:
> > smatrix = kwant.smatrix(sys, energy)
> > data.append(smatrix.transmission(1, 0))
> >
> > pyplot.figure()
> > pyplot.plot(energies, data)
> > pyplot.xlabel("energy [t]")
> > pyplot.ylabel("conductance [e^2/h]")
> > pyplot.show()
> >
> >
> > def main():
> > sys = make_system()
> >
> > # Check that the system looks as intended.
> > kwant.plot(sys)
> >
> > # Finalize the system.
> > sys = sys.finalized()
> >
> > # We should see non-monotonic conductance steps.
> > plot_conductance(sys, energies=[0.01 * i - 0.3 for i in xrange(100)])
> >
> >
> > # Call the main function if the script gets executed (as opposed to
> > imported).
> > # See <http://docs.python.org/library/__main__.html>.
> > if __name__ == '__main__':
> > main()
> >
> > Best Regards,
> >
> > Alexis
> >
> >> From: anton.akhmerov@gmail.com
> >> Date: Thu, 25 Jun 2015 11:28:58 +0200
> >> Subject: Re: [Kwant] Spin
> >> To: alexis-bozio@hotmail.fr
> >> CC: kwant-discuss@kwant-project.org
> >
> >>
> >> Hi Alexis,
> >>
> >> Can you share the code that you wrote? Is there any error being raised?
> >>
> >> Can you check if your kwant installation is working? To do so execute
> >>
> >> import kwant
> >> kwant.test()
> >>
> >> and check the output.
> >>
> >> Best,
> >> Anton
> >>
> >> On Thu, Jun 25, 2015 at 11:25 AM, Alexis Bozio <alexis-bozio@hotmail.fr>
> >> wrote:
> >> > Hello,
> >> >
> >> > I'm trying to calculate transmission function including spin with Matrix
> >> > for
> >> > onsite values but when i am writting the code that is explained on the
> >> > site
> >> > (http://kwant-project.org/doc/1.0/tutorial/tutorial2) it makes the
> >> > calculation but a few seconds later Python stops and all the datas
> >> > vanishe.
> >> > Thank you for your help.
> >> > Best Regards.
> >> > Alexis Bozio