sisl.physics.Spin

class sisl.physics.Spin

Bases: object

Spin class to determine configurations and spin components.

The basic class Spin implements a generic method to determine a spin configuration.

Its usage can be summarized in these few examples:

>>> Spin(Spin.UNPOLARIZED) == Spin("unpolarized") == Spin()
True
>>> Spin(Spin.POLARIZED) == Spin("polarized") == Spin("p")
True
>>> Spin(Spin.NONCOLINEAR, dtype=np.complex128) == Spin("non-collinear") == Spin("nc")
True
>>> Spin(Spin.SPINORBIT, dtype=np.complex128) == Spin("spin-orbit") == Spin("so") == Spin("soc")
True
>>> Spin(Spin.NAMBU) == Spin("nambu") == Spin("bdg")
True

Note that a data-type may be associated with a spin-object. This is not to say that the data-type is used in the configuration, but merely that it helps any sub-classed or classes who use the spin-object to determine the usage of the different spin-components.

Parameters:: kind (str or int, Spin, optional) – specify the spin kind

Methods

`copy`()	Create a copy of the spin-object
`size`(dtype)	Number of elements to describe the spin-components

Attributes

`NAMBU`
`NONCOLINEAR`
`POLARIZED`
`SPINORBIT`
`UNPOLARIZED`
`X`
`Y`
`Z`
`is_colinear`	True if the configuration is polarized
`is_diagonal`	Whether the spin-box is only using the diagonal components
`is_nambu`	True if the configuration is Nambu
`is_noncolinear`	True if the configuration non-collinear
`is_polarized`	True if the configuration is polarized
`is_spinorbit`	True if the configuration is spin-orbit
`is_unpolarized`	True if the configuration is not polarized
`kind`	A unique ID for the kind of spin configuration
`spinor`	Number of spinor components (1, 2 or 4)

copy()[source]: Create a copy of the spin-object

size(dtype)[source]

Number of elements to describe the spin-components

Parameters:: dtype (np.dtype) – data-type used to represent the spin-configuration
Return type:: int

NAMBU = 4

NONCOLINEAR = 2

POLARIZED = 1

SPINORBIT = 3

UNPOLARIZED = 0

X = array([[0.+0.j, 1.+0.j], [1.+0.j, 0.+0.j]])

Y = array([[ 0.+0.j, -0.-1.j], [ 0.+1.j, 0.+0.j]])

Z = array([[ 1.+0.j, 0.+0.j], [ 0.+0.j, -1.+0.j]])

property is_colinear: bool: True if the configuration is polarized

property is_diagonal: bool

Whether the spin-box is only using the diagonal components

This will return true for non-polarized and polarized spin configurations. Otherwise false.

property is_nambu: bool: True if the configuration is Nambu

property is_noncolinear: bool: True if the configuration non-collinear

property is_polarized: bool: True if the configuration is polarized

property is_spinorbit: bool: True if the configuration is spin-orbit

property is_unpolarized: bool: True if the configuration is not polarized

property kind: int: A unique ID for the kind of spin configuration

property spinor: int: Number of spinor components (1, 2 or 4)