Hi Wei,

Please check tutorial for dealing with conserved quantities, that we
introduced in the latest version of Kwant. That approach allows you to
easily compute spin conductance along any direction (and you don't
have to manually introduce sublattices). For more details please see
the tutorial: https://kwant-project.org/doc/1/tutorial/superconductors#superconductors-orbital-degrees-of-freedom-conservation-laws-and-symmetries

Best,
Anton

On Tue, Jan 23, 2018 at 1:27 PM, Wei Chen <pchenweis@gmail.com> wrote:
> Hi all,
>
> I am working on a spin resolved scattering problem using Kwant. The setup is
> a simple heterojunction composed of normal metal and spin-orbit coupled
> systems. I want to calculate the probabilities of spin-flipped and
> spin-conserved reflection. In the normal metal, I use two lattices for
> spin-up and spin-down states, and the calculation went well. The
> probabilities for spin-flipped and spin-conserved reflection can be read
> through inter- and intra-lattice scattering. Now I want to calculate the
> scattering problem for an incident wave with spin polarization in the
> x-direction.
>
> My question: how to set the incident spin state along the x-direction and
> calculate the corresponding spin-flipped (spin in -x direction) and
> spin-conserved scattering probabilities?
>
> Thanks very much!
>
> Best,
> Wei
>
>
>
> --
>
> College of Science, University of Aeronautics and Astronautics, Nanjing,
> 210016, P. R. China
>
> E-mail: pchenweis@gmail.com,
>
>             weichenphy@nuaa.edu.cn