diff --git a/kwant/builder.py b/kwant/builder.py
index 05ee58f7398b8dec5ba3c712e20e656968962f70..156c97f65d3dd08833d5c66aaf7f1e93372f39c2 100644
--- a/kwant/builder.py
+++ b/kwant/builder.py
@@ -482,7 +482,7 @@ class Builder:
Parameters
----------
- symmetry : `Symmetry` or `None`
+ symmetry : `~kwant.system.Symmetry` or `None`
The spatial symmetry of the system.
conservation_law : 2D array, dictionary, function, or `None`
An onsite operator with integer eigenvalues that commutes with the
@@ -531,8 +531,8 @@ class Builder:
that if ``builder[a, b]`` has been set, there is no need to set
``builder[b, a]``.
- Builder instances can be made to automatically respect a `Symmetry` that is
- passed to them during creation. The behavior of builders with a symmetry
+ Builder instances can be made to automatically respect a `~kwant.system.Symmetry`
+ that is passed to them during creation. The behavior of builders with a symmetry
is slightly more sophisticated: all keys are mapped to the fundamental
domain of the symmetry before storing them. This may produce confusing
results when neighbors of a site are queried.
@@ -1481,7 +1481,7 @@ class Builder:
system to be returned.
Currently, only Builder instances without or with a 1D translational
- `Symmetry` can be finalized.
+ `~kwant.system.Symmetry` can be finalized.
"""
if self.symmetry.num_directions == 0:
if self.vectorize:
diff --git a/kwant/continuum/landau_levels.py b/kwant/continuum/landau_levels.py
index c653c55ef2634cd13e932f0c3f9c5fd026c10ff9..b2b8fc802dfa03343c4d7d314d84203c7c581302 100644
--- a/kwant/continuum/landau_levels.py
+++ b/kwant/continuum/landau_levels.py
@@ -18,6 +18,7 @@ import sympy
import kwant.lattice
import kwant.builder
+import kwant.system
import kwant.continuum
import kwant.continuum._common
@@ -144,7 +145,7 @@ def discretize_landau(hamiltonian, N, momenta=None, grid_spacing=1):
if _has_coordinate(normal_coordinate, hamiltonian):
sym = kwant.lattice.TranslationalSymmetry([grid_spacing, 0])
else:
- sym = kwant.builder.NoSymmetry()
+ sym = kwant.system.NoSymmetry()
lat = LandauLattice(grid_spacing, norbs=norbs)
syst = kwant.Builder(sym)
diff --git a/kwant/continuum/tests/test_landau_levels.py b/kwant/continuum/tests/test_landau_levels.py
index 8a568e6f4a4a716f1daa2c82542f47ea237a0f9d..5878724fbf997949d791dc33ae49a90e55b24a39 100644
--- a/kwant/continuum/tests/test_landau_levels.py
+++ b/kwant/continuum/tests/test_landau_levels.py
@@ -13,8 +13,8 @@ import sympy
import pytest
import itertools
-import kwant.builder
import kwant.lattice
+import kwant.system
from .._common import position_operators, momentum_operators, sympify
from ..landau_levels import (
@@ -118,7 +118,7 @@ def test_discretize_landau():
# test a basic Hamiltonian with no normal coordinate dependence
syst = discretize_landau("k_x**2 + k_y**2", N=n_levels)
lat = LandauLattice(1, norbs=1)
- assert isinstance(syst.symmetry, kwant.builder.NoSymmetry)
+ assert isinstance(syst.symmetry, kwant.system.NoSymmetry)
syst = syst.finalized()
assert set(syst.sites) == {lat(0, j) for j in range(n_levels)}
assert np.allclose(
diff --git a/kwant/lattice.py b/kwant/lattice.py
index 7e0d55905df3292b5e4eeee7812ed7649d952f77..976213d3578899a497e06da357aa512d8289f24d 100644
--- a/kwant/lattice.py
+++ b/kwant/lattice.py
@@ -153,7 +153,7 @@ class Polyatomic:
algorithm finds and yields all the lattice sites inside the specified
shape starting from the specified position.
- A `~kwant.builder.Symmetry` or `~kwant.builder.Builder` may be passed as
+ A `~kwant.system.Symmetry` or `~kwant.builder.Builder` may be passed as
sole argument when calling the function returned by this method. This
will restrict the flood-fill to the fundamental domain of the symmetry
(or the builder's symmetry). Note that unless the shape function has
@@ -174,8 +174,8 @@ class Polyatomic:
Site = system.Site
if symmetry is None:
- symmetry = builder.NoSymmetry()
- elif not isinstance(symmetry, builder.Symmetry):
+ symmetry = system.NoSymmetry()
+ elif not isinstance(symmetry, system.Symmetry):
symmetry = symmetry.symmetry
def fd_site(lat, tag):
@@ -259,7 +259,7 @@ class Polyatomic:
center = ta.array(center, float)
def wire_sites(sym):
- if not isinstance(sym, builder.Symmetry):
+ if not isinstance(sym, system.Symmetry):
sym = sym.symmetry
if not isinstance(sym, TranslationalSymmetry):
raise ValueError('wire shape only works with '
@@ -568,7 +568,7 @@ class TranslationalSymmetry(system.Symmetry):
return TranslationalSymmetry(*ta.dot(generators, self.periods))
def has_subgroup(self, other):
- if isinstance(other, builder.NoSymmetry):
+ if isinstance(other, system.NoSymmetry):
return True
elif not isinstance(other, TranslationalSymmetry):
raise ValueError("Unknown symmetry type.")
diff --git a/kwant/physics/tests/test_gauge.py b/kwant/physics/tests/test_gauge.py
index 067c3244d44363ffcf6e9e4f993485b465e10e34..40e5f66d7560ad8c6f70111ac1dd73c7b89411bb 100644
--- a/kwant/physics/tests/test_gauge.py
+++ b/kwant/physics/tests/test_gauge.py
@@ -6,7 +6,8 @@ import pytest
import kwant
from ... import lattice
-from ...builder import HoppingKind, Builder, NoSymmetry, Site
+from ...builder import HoppingKind, Builder, Site
+from ...system import NoSymmetry
from .. import gauge
diff --git a/kwant/tests/test_builder.py b/kwant/tests/test_builder.py
index 3355a4ff0eacb4b68e7286961231051a7a858e47..f4a70985af7719a89693a5d0145f3a4b5ec24f6d 100644
--- a/kwant/tests/test_builder.py
+++ b/kwant/tests/test_builder.py
@@ -153,7 +153,7 @@ def test_site_families():
assert fam1 < fam2 # string '1' is lexicographically less than '2'
-class VerySimpleSymmetry(builder.Symmetry):
+class VerySimpleSymmetry(system.Symmetry):
def __init__(self, period):
self.period = period
@@ -162,7 +162,7 @@ class VerySimpleSymmetry(builder.Symmetry):
return 1
def has_subgroup(self, other):
- if isinstance(other, builder.NoSymmetry):
+ if isinstance(other, system.NoSymmetry):
return True
elif isinstance(other, VerySimpleSymmetry):
return not other.period % self.period
@@ -809,7 +809,7 @@ def test_vectorized_value_normalization():
@pytest.mark.parametrize("sym", [
- builder.NoSymmetry(),
+ system.NoSymmetry(),
kwant.TranslationalSymmetry([-1]),
])
def test_vectorized_requires_norbs(sym):
@@ -918,7 +918,7 @@ def test_fill():
## Test that copying a builder by "fill" preserves everything.
for sym, func in [(kwant.TranslationalSymmetry(*np.diag([3, 4, 5])),
lambda pos: True),
- (builder.NoSymmetry(),
+ (system.NoSymmetry(),
lambda pos: ta.dot(pos, pos) < 17)]:
cubic = kwant.lattice.general(ta.identity(3), norbs=1)
@@ -1639,7 +1639,7 @@ def test_subs():
lat = kwant.lattice.chain(norbs=1)
- def make_system(sym=kwant.builder.NoSymmetry(), n=3):
+ def make_system(sym=system.NoSymmetry(), n=3):
syst = kwant.Builder(sym)
syst[(lat(i) for i in range(n))] = onsite
syst[lat.neighbors()] = hopping
diff --git a/kwant/tests/test_lattice.py b/kwant/tests/test_lattice.py
index 5e7a9976ed74ef881ece72ada167c48c39f8ff13..4850e45137076dbe05615225530e2d8b1e671eed 100644
--- a/kwant/tests/test_lattice.py
+++ b/kwant/tests/test_lattice.py
@@ -11,7 +11,7 @@ from math import sqrt
import numpy as np
import tinyarray as ta
from pytest import raises
-from kwant import lattice, builder
+from kwant import lattice, builder, system
from kwant._common import ensure_rng
import pytest
@@ -285,7 +285,7 @@ def test_symmetry_has_subgroup():
## test whether actual subgroups are detected as such
vecs = rng.randn(3, 3)
sym1 = lattice.TranslationalSymmetry(*vecs)
- ns = builder.NoSymmetry()
+ ns = system.NoSymmetry()
assert ns.has_subgroup(ns)
assert sym1.has_subgroup(sym1)
assert sym1.has_subgroup(ns)