Good day,
I'm trying to reconstruct something discussed in
http://www.mail-archive.com/[email protected]/msg00432.html.
In this answer it is described how to take the wavefunction from a 3D
system and plot it in a 2D slice. This turned out to be something different
than what the OP was asking for, but that is not so important. It is also
mentioned that this has been asked before, but I couldn't find the right
search terms. If my question has already been answered, I'd be very
grateful for a referral to the relevant discussion!
Now, as it turns out, I can't seem to get the above to work. I take some
small cylinder, I calculate the wavefunction, but then I get stuck at how
to extract for example the y = 0 plane and plot this in 2D. Below I'll post
how far I got, perhaps the fix would be rather simple.
def onsite(site, p):
return 6*p.t
def hopping(site0, site1, p):
return -p.t
def make_system_cyl(a=1, s=10, L = 15):
lat = kwant.lattice.general([(0, 0, a), (a, 0, 0), (0, a, 0)])
sys = kwant.Builder()
def cyl_shape(pos):
x, y, z = pos
rsq = y ** 2 + z ** 2
return rsq < s^2 and 0 <= x < L
sys[lat.shape(cyl_shape, (1,1,1))] = onsite
sys[lat.neighbors()] = hopping
def lead_shape(pos):
x, y, z = pos
rsq = y ** 2 + z ** 2
return rsq < s^2
sym_lead = kwant.TranslationalSymmetry((-a,0,0))
lead = kwant.Builder(sym_lead)
lead[lat.shape(lead_shape, (-a,1,1))] = onsite
lead[lat.neighbors()] = hopping
sys.attach_lead(lead)
sys.attach_lead(lead.reversed())
return sys
and I extract the wavefunction at some energy
sys = make_system_cyl(a=1, s=10, L = 15)
kwant.plot(sys)
sysf = sys.finalized()
params = SimpleNamespace(t=1)
wf = kwant.wave_function(sysf, 1.5, args=[params])
And then I try to extract the relevant parts
wavefunction = wf(0)
projected_wavefunction = np.empty((wavefunction.size, 1), dtype=np.complex)
def in_sheet(index, site):
return site.pos[1] == 0 # site in x-z plane
sheet_idx_sites = filter(in_sheet, enumerate(sys.sites)
for i, (idx, site) in enumerate(sheet_idx_sites):
projected_wavefunction[i] = wavefunction[idx]
Now this last part I took from the post referenced at the start, and it
gives a syntax error. I'm not really sure how to fix it as it looks fine to
me. What's wrong there?
And more importantly, once this is fixed, how can one then make a
kwant.plotter.map type of plot at this x-z plane?
