Dear Anant,

Your questions are more about general physics than about kwant and I don't think they really belong on this mailing-list.

If you want to study temperature effects you have to include the physics yourself. Suppose you want to study temperature using statistical mechanics you can easily define an ensemble average (an average over all energies weighted by a fermi-dirac function), but if you want to study the melting behaviour of graphene you'll have to resort to something else.

As for the magnetic field: look up on something called ``Peierls substitution''. Instead of using the Landau gauge, you might want to consider the ``optimal'' gauge as defined here.

cheers,

Robert

On Sat, Oct 4, 2014 at 1:50 PM, ANANT <avterminator@gmail.com> wrote:

Dear all,
Can we really use temperature variable in KWANT? If yes,then with
what function.Also, How to apply magnetic field perpendicular to the sample
like I am having the graphene sheet and I want to apply per mag. field on
it.this is what I am trying!
################################################
def hopx(site1, site2, B=0):
# The magnetic field is controlled by the parameter B
y = site1.pos[1]
return -t * exp(-1j * B * y)
sys[lat.shape(circle, (0, 0))] = 4 * t
# hoppings in x-direction
sys[kwant.builder.HoppingKind((1, 0), lat, lat)] = hopx
# hoppings in y-directions
sys[kwant.builder.HoppingKind((0, 1), lat, lat)] = -t
# It’s a closed system for a change, so no leads
##################################################