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Commit a4aca30b authored by Anton Akhmerov's avatar Anton Akhmerov Committed by Christoph Groth
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Change possible_hoppings -> HoppingKind in tutorial

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with 48 additions and 67 deletions
doc/source/images/ab_ring.py.diff
+ 10
− 14
View file @ a4aca30b
......@@ -8,9 +8,9 @@
def make_system(a=1, t=1.0, W=10, r1=10, r2=20):
@@ -38,12 +39,13 @@
for hopping in lat.nearest:
sys[sys.possible_hoppings(*hopping)] = -t
@@ -37,12 +38,13 @@
sys[lat.shape(ring, (0, r1 + 1))] = 4 * t
sys[lat.nearest] = -t
- # In order to introduce a flux through the ring, we introduce a phase on
- # the hoppings on the line cut through one of the arms. Since we want to
......@@ -28,7 +28,7 @@
return exp(1j * phi)
def crosses_branchcut(hop):
@@ -81,6 +83,54 @@
@@ -82,6 +84,50 @@
return sys
......@@ -40,16 +40,14 @@
+ rsq = x**2 + y**2
+ return ( r1**2 < rsq < r2**2)
+ sys[lat.shape(ring, (0, 11))] = 4 * t
+ for hopping in lat.nearest:
+ sys[sys.possible_hoppings(*hopping)] = -t
+ sys[lat.nearest] = -t
+ sym_lead0 = kwant.TranslationalSymmetry((-a, 0))
+ lead0 = kwant.Builder(sym_lead0)
+ def lead_shape(pos):
+ (x, y) = pos
+ return (-1 < x < 1) and ( 0.5 * W < y < 1.5 * W )
+ lead0[lat.shape(lead_shape, (0, W))] = 4 * t
+ for hopping in lat.nearest:
+ lead0[lead0.possible_hoppings(*hopping)] = -t
+ lead0[lat.nearest] = -t
+ lead1 = lead0.reversed()
+ sys.attach_lead(lead0)
+ sys.attach_lead(lead1)
......@@ -64,16 +62,14 @@
+ rsq = x**2 + y**2
+ return ( r1**2 < rsq < r2**2)
+ sys[lat.shape(ring, (0, 11))] = 4 * t
+ for hopping in lat.nearest:
+ sys[sys.possible_hoppings(*hopping)] = -t
+ sys[lat.nearest] = -t
+ sym_lead0 = kwant.TranslationalSymmetry((-a, 0))
+ lead0 = kwant.Builder(sym_lead0)
+ def lead_shape(pos):
+ (x, y) = pos
+ return (-1 < x < 1) and ( -W/2 < y < W/2 )
+ lead0[lat.shape(lead_shape, (0, 0))] = 4 * t
+ for hopping in lat.nearest:
+ lead0[lead0.possible_hoppings(*hopping)] = -t
+ lead0[lat.nearest] = -t
+ lead1 = lead0.reversed()
+ sys.attach_lead(lead0)
+ sys.attach_lead(lead1, lat(0, 0))
......@@ -83,7 +79,7 @@
def plot_conductance(sys, energy, fluxes):
# compute conductance
@@ -90,18 +140,29 @@
@@ -91,18 +137,29 @@
smatrix = kwant.solve(sys, energy, kwargs={'phi': flux})
data.append(smatrix.transmission(1, 0))
......@@ -118,7 +114,7 @@
# Finalize the system.
sys = sys.finalized()
@@ -111,6 +172,15 @@
@@ -112,6 +169,15 @@
for i in xrange(100)])
......
doc/source/images/graphene.py.diff
+ 2
− 11
View file @ a4aca30b
......@@ -8,16 +8,7 @@
# Define the graphene lattice
@@ -63,7 +64,7 @@
return (-1 < x < 1) and (-0.4 * r < y < 0.4 * r)
lead0 = kwant.Builder(sym0)
- lead0[graphene.shape(lead0_shape, (0, 0))] = -pot
+ lead0[graphene.shape(lead0_shape, (0, 0))] = - pot
for hopping in hoppings:
lead0[lead0.possible_hoppings(*hopping)] = -1
@@ -105,22 +106,40 @@
@@ -102,22 +103,40 @@
smatrix = kwant.solve(sys, energy)
data.append(smatrix.transmission(0, 1))
......@@ -66,7 +57,7 @@
def main():
@@ -133,17 +152,22 @@
@@ -130,17 +149,22 @@
return 0 if site.group == a else 1
# Plot the closed system without leads.
......
doc/source/images/quantum_well.py.diff
+ 1
− 1
View file @ a4aca30b
......@@ -8,7 +8,7 @@
def make_system(a=1, t=1.0, W=10, L=30, L_well=10):
@@ -63,19 +64,25 @@
@@ -61,19 +62,25 @@
smatrix = kwant.solve(sys, energy, kwargs={'pot': -welldepth})
data.append(smatrix.transmission(1, 0))
......
doc/source/tutorial/ab_ring.py
+ 8
− 7
View file @ a4aca30b
......@@ -38,8 +38,7 @@ def make_system(a=1, t=1.0, W=10, r1=10, r2=20):
# and add the corresponding lattice points using the `shape`-function
#HIDDEN_BEGIN_lcak
sys[lat.shape(ring, (0, r1 + 1))] = 4 * t
for hopping in lat.nearest:
sys[sys.possible_hoppings(*hopping)] = -t
sys[lat.nearest] = -t
#HIDDEN_END_lcak
# In order to introduce a flux through the ring, we introduce a phase on
......@@ -54,13 +53,16 @@ def make_system(a=1, t=1.0, W=10, r1=10, r2=20):
def crosses_branchcut(hop):
ix0, iy0 = hop[0].tag
# possible_hoppings with the argument (1, 0) below
# builder.HoppingKind with the argument (1, 0) below
# returns hoppings ordered as ((i+1, j), (i, j))
return iy0 < 0 and ix0 == 1 # ix1 == 0 then implied
# Modify only those hopings in x-direction that cross the branch cut
sys[(hop for hop in sys.possible_hoppings((1, 0), lat, lat)
if crosses_branchcut(hop))] = fluxphase
def hops_across_cut(sys):
for hop in kwant.builder.HoppingKind((1, 0), lat, lat)(sys):
if crosses_branchcut(hop):
yield hop
sys[hops_across_cut] = fluxphase
#HIDDEN_END_lvkt
#### Define the leads. ####
......@@ -74,8 +76,7 @@ def make_system(a=1, t=1.0, W=10, r1=10, r2=20):
return (-1 < x < 1) and (-W / 2 < y < W / 2)
lead0[lat.shape(lead_shape, (0, 0))] = 4 * t
for hopping in lat.nearest:
lead0[lead0.possible_hoppings(*hopping)] = -t
lead0[lat.nearest] = -t
#HIDDEN_END_qwgr
# Then the lead to the right
......
doc/source/tutorial/closed_system.py
+ 2
− 2
View file @ a4aca30b
......@@ -43,9 +43,9 @@ def make_system(a=1, t=1.0, r=10):
sys[lat.shape(circle, (0, 0))] = 4 * t
# hoppings in x-direction
sys[sys.possible_hoppings((1, 0), lat, lat)] = hopx
sys[kwant.builder.HoppingKind((1, 0), lat, lat)] = hopx
# hoppings in y-directions
sys[sys.possible_hoppings((0, 1), lat, lat)] = -t
sys[kwant.builder.HoppingKind((0, 1), lat, lat)] = -t
# It's a closed system for a change, so no leads
return sys
......
doc/source/tutorial/graphene.py
+ 4
− 7
View file @ a4aca30b
......@@ -49,13 +49,12 @@ def make_system(r=10, w=2.0, pot=0.1):
#HIDDEN_END_shzy
# specify the hoppings of the graphene lattice in the
# format expected by possibe_hoppings()
# format expected by builder.HoppingKind
#HIDDEN_BEGIN_hsmc
hoppings = (((0, 0), a, b), ((0, 1), a, b), ((-1, 1), a, b))
#HIDDEN_END_hsmc
#HIDDEN_BEGIN_bfwb
for hopping in hoppings:
sys[sys.possible_hoppings(*hopping)] = -1
sys[[kwant.builder.HoppingKind(*hopping) for hopping in hoppings]] = -1
#HIDDEN_END_bfwb
# Modify the scattering region
......@@ -75,8 +74,7 @@ def make_system(r=10, w=2.0, pot=0.1):
lead0 = kwant.Builder(sym0)
lead0[graphene.shape(lead0_shape, (0, 0))] = -pot
for hopping in hoppings:
lead0[lead0.possible_hoppings(*hopping)] = -1
lead0[[kwant.builder.HoppingKind(*hopping) for hopping in hoppings]] = -1
# The second lead, going to the top right
sym1 = kwant.TranslationalSymmetry(graphene.vec((0, 1)))
......@@ -89,8 +87,7 @@ def make_system(r=10, w=2.0, pot=0.1):
lead1 = kwant.Builder(sym1)
lead1[graphene.shape(lead1_shape, (0, 0))] = pot
for hopping in hoppings:
lead1[lead1.possible_hoppings(*hopping)] = -1
lead1[[kwant.builder.HoppingKind(*hopping) for hopping in hoppings]] = -1
#HIDDEN_END_aakh
#HIDDEN_BEGIN_kmmw
......
doc/source/tutorial/quantum_well.py
+ 2
− 4
View file @ a4aca30b
......@@ -35,8 +35,7 @@ def make_system(a=1, t=1.0, W=10, L=30, L_well=10):
return 4 * t + potential(site, pot)
sys[(lat(x, y) for x in range(L) for y in range(W))] = onsite
for hopping in lat.nearest:
sys[sys.possible_hoppings(*hopping)] = -t
sys[lat.nearest] = -t
#HIDDEN_END_coid
#### Define the leads. ####
......@@ -45,8 +44,7 @@ def make_system(a=1, t=1.0, W=10, L=30, L_well=10):
lead0 = kwant.Builder(sym_lead0)
lead0[(lat(0, j) for j in xrange(W))] = 4 * t
for hopping in lat.nearest:
lead0[lead0.possible_hoppings(*hopping)] = -t
lead0[lat.nearest] = -t
# ... then the lead to the right. We use a method that returns a copy of
# `lead0` with its direction reversed.
......
doc/source/tutorial/quantum_wire_revisited.py
+ 3
− 5
View file @ a4aca30b
......@@ -4,7 +4,7 @@
#
# Kwant features highlighted
# --------------------------
# - Using iterables and possible_hoppings() for making systems
# - Using iterables and builder.HoppingKind for making systems
# - introducing `reversed()` for the leads
#
# Note: Does the same as tutorial1a.py, but using other features of kwant
......@@ -29,8 +29,7 @@ def make_system(a=1, t=1.0, W=10, L=30):
sys[(lat(x, y) for x in range(L) for y in range(W))] = 4 * t
#HIDDEN_END_vvjt
#HIDDEN_BEGIN_nooi
for hopping in lat.nearest:
sys[sys.possible_hoppings(*hopping)] = -t
sys[lat.nearest] = -t
#HIDDEN_END_nooi
#### Define the leads. ####
......@@ -41,8 +40,7 @@ def make_system(a=1, t=1.0, W=10, L=30):
lead0 = kwant.Builder(sym_lead0)
lead0[(lat(0, j) for j in xrange(W))] = 4 * t
for hopping in lat.nearest:
lead0[lead0.possible_hoppings(*hopping)] = -t
lead0[lat.nearest] = -t
#HIDDEN_END_iepx
# ... then the lead to the right. We use a method that returns a copy of
......
doc/source/tutorial/spin_orbit.py
+ 4
− 4
View file @ a4aca30b
......@@ -41,10 +41,10 @@ def make_system(a=1, t=1.0, alpha=0.5, e_z=0.08, W=10, L=30):
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[sys.possible_hoppings((1, 0), lat, lat)] = -t * sigma_0 - \
sys[kwant.builder.HoppingKind((1, 0), lat, lat)] = -t * sigma_0 - \
1j * alpha * sigma_y
# hoppings in y-directions
sys[sys.possible_hoppings((0, 1), lat, lat)] = -t * sigma_0 + \
sys[kwant.builder.HoppingKind((0, 1), lat, lat)] = -t * sigma_0 + \
1j * alpha * sigma_x
#HIDDEN_END_uxrm
......@@ -56,10 +56,10 @@ def make_system(a=1, t=1.0, alpha=0.5, e_z=0.08, W=10, L=30):
#HIDDEN_BEGIN_yliu
lead0[(lat(0, j) for j in xrange(W))] = 4 * t * sigma_0 + e_z * sigma_z
# hoppings in x-direction
lead0[lead0.possible_hoppings((1, 0), lat, lat)] = -t * sigma_0 - \
lead0[kwant.builder.HoppingKind((1, 0), lat, lat)] = -t * sigma_0 - \
1j * alpha * sigma_y
# hoppings in y-directions
lead0[lead0.possible_hoppings((0, 1), lat, lat)] = -t * sigma_0 + \
lead0[kwant.builder.HoppingKind((0, 1), lat, lat)] = -t * sigma_0 + \
1j * alpha * sigma_x
#HIDDEN_END_yliu
......
doc/source/tutorial/superconductor_transport.py
+ 12
− 12
View file @ a4aca30b
......@@ -36,10 +36,10 @@ def make_system(a=1, W=10, L=10, barrier=1.5, barrierpos=(3, 4),
for y in range(W))] = mu - 4 * t - barrier
# hoppings in x and y-directions, for both electrons and holes
sys[sys.possible_hoppings((1, 0), lat_e, lat_e)] = -t
sys[sys.possible_hoppings((0, 1), lat_e, lat_e)] = -t
sys[sys.possible_hoppings((1, 0), lat_h, lat_h)] = t
sys[sys.possible_hoppings((0, 1), lat_h, lat_h)] = t
sys[kwant.builder.HoppingKind((1, 0), lat_e, lat_e)] = -t
sys[kwant.builder.HoppingKind((0, 1), lat_e, lat_e)] = -t
sys[kwant.builder.HoppingKind((1, 0), lat_h, lat_h)] = t
sys[kwant.builder.HoppingKind((0, 1), lat_h, lat_h)] = t
# Superconducting order parameter enters as hopping between
# electrons and holes
......@@ -56,15 +56,15 @@ def make_system(a=1, W=10, L=10, barrier=1.5, barrierpos=(3, 4),
lead0 = kwant.Builder(sym_left)
lead0[(lat_e(0, j) for j in xrange(W))] = 4 * t - mu
# hoppings in x and y-direction
lead0[lead0.possible_hoppings((1, 0), lat_e, lat_e)] = -t
lead0[lead0.possible_hoppings((0, 1), lat_e, lat_e)] = -t
lead0[kwant.builder.HoppingKind((1, 0), lat_e, lat_e)] = -t
lead0[kwant.builder.HoppingKind((0, 1), lat_e, lat_e)] = -t
# left hole lead
lead1 = kwant.Builder(sym_left)
lead1[(lat_h(0, j) for j in xrange(W))] = mu - 4 * t
# hoppings in x and y-direction
lead1[lead1.possible_hoppings((1, 0), lat_h, lat_h)] = t
lead1[lead1.possible_hoppings((0, 1), lat_h, lat_h)] = t
lead1[kwant.builder.HoppingKind((1, 0), lat_h, lat_h)] = t
lead1[kwant.builder.HoppingKind((0, 1), lat_h, lat_h)] = t
#HIDDEN_END_ttth
# Then the lead to the right
......@@ -77,10 +77,10 @@ def make_system(a=1, W=10, L=10, barrier=1.5, barrierpos=(3, 4),
lead2[(lat_e(0, j) for j in xrange(W))] = 4 * t - mu
lead2[(lat_h(0, j) for j in xrange(W))] = mu - 4 * t
# hoppings in x and y-direction
lead2[lead2.possible_hoppings((1, 0), lat_e, lat_e)] = -t
lead2[lead2.possible_hoppings((0, 1), lat_e, lat_e)] = -t
lead2[lead2.possible_hoppings((1, 0), lat_h, lat_h)] = t
lead2[lead2.possible_hoppings((0, 1), lat_h, lat_h)] = t
lead2[kwant.builder.HoppingKind((1, 0), lat_e, lat_e)] = -t
lead2[kwant.builder.HoppingKind((0, 1), lat_e, lat_e)] = -t
lead2[kwant.builder.HoppingKind((1, 0), lat_h, lat_h)] = t
lead2[kwant.builder.HoppingKind((0, 1), lat_h, lat_h)] = t
lead2[((lat_e(0, j), lat_h(0, j)) for j in xrange(W))] = Delta
#HIDDEN_END_mhiw
......
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