kwant.system.NoSymmetry

class kwant.system.NoSymmetry[source]

Bases: kwant.system.Symmetry

A symmetry with a trivial symmetry group.

Methods

act(element, a, b=None)[source]

Act with symmetry group element(s) on site(s) or hopping(s).

Parameters
elementtuple or sequence of tuples

Group element(s) with which to act on the provided site(s) or hopping(s)

a, bSite or SiteArray

If Site then element is a single tuple, if SiteArray then element is a single tuple or a sequence of tuples. If only a is provided then element acts on the site(s) of a. If b is also provided then element acts on the hopping(s) (a, b).

has_subgroup(other)[source]

Test whether self has the subgroup other

or, in other words, whether other is a subgroup of self. The reason why this is the abstract method (and not is_subgroup) is that in general it’s not possible for a subgroup to know its supergroups.

in_fd(site)[source]

Tell whether site lies within the fundamental domain.

Parameters
siteSite or SiteArray
Returns
in_fdbool or sequence of bool

single bool if site is a Site, or a sequence of bool if site is a SiteArray. In the latter case we return whether each site in the SiteArray is in the fundamental domain.

subgroup(*generators)[source]

Return the subgroup generated by a sequence of group elements.

to_fd(a, b=None)[source]

Map a site or hopping to the fundamental domain.

Parameters
a, bSite or SiteArray
If ``b`` is None, return a site equivalent to ``a`` within the
fundamental domain. Otherwise, return a hopping equivalent to ``(a,
b)`` but where the first element belongs to the fundamental domain.
Equivalent to `self.act(-self.which(a), a, b)`.
which(site)[source]

Calculate the domain of the site.

Parameters
siteSite or SiteArray
Returns
group_elementtuple or sequence of tuples

A single tuple if site is a Site, or a sequence of tuples if site is a SiteArray. The group element(s) whose action on a certain site(s) from the fundamental domain will result in the given site.

Attributes

num_directions[source]
periods = ()[source]

Previous topic

kwant.system.Symmetry

Next topic

kwant.system.System

This Page