From 30c3d08a83f08053e1cdc7f19d5f588f2e354176 Mon Sep 17 00:00:00 2001
From: Christoph Groth <christoph.groth@cea.fr>
Date: Tue, 7 May 2013 11:12:30 +0200
Subject: [PATCH] make examples/advanced_construction.py work again
---
examples/advanced_construction.py | 37 ++++++++++++++++---------------
1 file changed, 19 insertions(+), 18 deletions(-)
diff --git a/examples/advanced_construction.py b/examples/advanced_construction.py
index deb35103..a1d17f1f 100644
--- a/examples/advanced_construction.py
+++ b/examples/advanced_construction.py
@@ -1,38 +1,39 @@
"""An example of advanced system creation."""
from __future__ import division
-import kwant
-import tinyarray as ta
from math import tanh
+import tinyarray as ta
+import kwant
+
+sigma_0 = ta.identity(2)
+sigma_x = ta.array([[0, 1], [1, 0]])
+sigma_y = ta.array([[0, -1j], [1j, 0]])
+sigma_z = ta.array([[1, 0], [0, -1]])
-def make_system(R=50):
- sigma_0 = ta.identity(2)
- sigma_x = ta.array([[0, 1], [1, 0]])
- sigma_y = ta.array([[0, -1j], [1j, 0]])
- sigma_z = ta.array([[1, 0], [0, -1]])
+def make_system(R):
def in_ring(pos):
- return R ** 2 / 4 < pos[0] ** 2 + pos[1] ** 2 < R ** 2
+ x, y = pos
+ return R**2 / 4 < x**2 + y**2 < R**2
+
+ def in_lead(pos):
+ x, y = pos
+ return -R / 4 < y < R / 4
def pot(site):
x, y = site.pos
return (0.1 * tanh(x / R) + tanh(2 * y / R)) * sigma_z
- def in_lead(pos):
- return -1 < pos[0] < 1.3 and -R / 4 < pos[1] < R / 4
-
- lat = kwant.lattice.Honeycomb()
+ lat = kwant.lattice.honeycomb()
sys = kwant.Builder()
sys[lat.shape(in_ring, (3 * R / 4, 0))] = pot
- for hopping in lat.nearest:
- sys[sys.possible_hoppings(*hopping)] = sigma_y
+ sys[lat.neighbors()] = sigma_y
lead = kwant.Builder(kwant.TranslationalSymmetry(lat.vec((-1, 0))))
lead[lat.shape(in_lead, (0, 0))] = sigma_0
- for hopping in lat.nearest:
- lead[lead.possible_hoppings(*hopping)] = sigma_x
+ lead[lat.neighbors()] = sigma_x
sys.attach_lead(lead)
sys.attach_lead(lead.reversed())
@@ -40,8 +41,8 @@ def make_system(R=50):
def main():
- fsys = make_system(100)
- print kwant.solve(fsys, 0.1).transmission(0, 1)
+ sys = make_system(100)
+ print kwant.solve(sys, 1.1).transmission(0, 1)
if __name__ == '__main__':
--
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