qimpy.transport.material.Material

class Material(*, wk, nk, n_bands, n_dim, process_grid, checkpoint_in=(None, ''))

Bases: TreeNode

Base class / interface for material specifications.

Parameters:

• wk (float) –

• nk (int) –

• n_bands (int) –

• n_dim (int) –

• process_grid (ProcessGrid) –

• checkpoint_in (CheckpointPath) –

__init__(*, wk, nk, n_bands, n_dim, process_grid, checkpoint_in=(None, ''))

Initialize material parameters, typically used from a derived class.

Parameters:

• wk (float) –

• nk (int) –

• n_bands (int) –

• n_dim (int) –

• process_grid (ProcessGrid) –

• checkpoint_in (CheckpointPath) –

Methods

__init__	Initialize material parameters, typically used from a derived class.
add_child	Construct child object self.`attr_name` of type cls.
add_child_one_of	Invoke add_child on one of several child options in args.
get_contactor	Return a function (or callable object) to calculate the distribution function at a contact with orientation n and specified keyword arguments.
get_observable_names	Return string of observables, comma seperated, specific to each material.
get_observables	Return tensor of complex conjugates of all observables specific to each material.
get_reflector	Return a function (or callable object) to calculate reflections for a sequence of surface points with unit normals (Nsurf x 2).
measure_observables	Retrun density and flux of observables, (Nx x Ny x No) for density and (Nx x Ny x No x 2) for flux.
rho_dot	Return material contribution to drho/dt.
save_checkpoint	Save self and all children in hierarchy to cp_path.

Attributes

transport_velocity	Effective velocity for each density-matrix component.
comm	Communicator for reciprocal-space split over k
k_division	Division of k-points over MPI
k_mine	slice of k on current process
n_bands	number of bands at each k
n_dim	dimensionality of material (2 or 3)
wk	Brillouin zone integration weight
k	nk x n_dim wave vectors
E	nk x n_bands energies
v	nk x n_bands x n_dim velocities in plane
rho0	nk x n_bands x n_bands initial density matrix
child_names	Names of attributes with child objects.

abstract get_contactor(n, **kwargs)

Return a function (or callable object) to calculate the distribution function at a contact with orientation n and specified keyword arguments. For an Nsurf x 2 tensor n, the function should take time t as an input and return the corresponding Nsurf x Nkbb_mine distribution function.

Parameters:

n (Tensor) –

Return type:

Callable[[float], Tensor]

abstract get_observable_names()

Return string of observables, comma seperated, specific to each material.

Return type:

list[str]

abstract get_observables(Nkbb, t)

Return tensor of complex conjugates of all observables specific to each material. (No x Nkbb_mine) where No is number of observables.

Parameters:

• Nkbb (int) –

• t (float) –

Return type:

Tensor

abstract get_reflector(n)

Return a function (or callable object) to calculate reflections for a sequence of surface points with unit normals (Nsurf x 2). This function will be called with a Nghost x Nsurf x Nkbb_mine tensor, and the reflection should be calculated pointwise in real-space with output of the same dimensions.

Parameters:

n (Tensor) –

Return type:

Callable[[Tensor], Tensor]

measure_observables(rho, t)

Retrun density and flux of observables, (Nx x Ny x No) for density and (Nx x Ny x No x 2) for flux.

Parameters:

• rho (Tensor) –

• t (float) –

Return type:

tuple[Tensor, Tensor]

abstract rho_dot(rho, t)

Return material contribution to drho/dt. This should include scattering and any coherent evolution in band space.

Parameters:

• rho (Tensor) –

• t (float) –

Return type:

Tensor

E: Tensor

nk x n_bands energies

comm: Comm

Communicator for reciprocal-space split over k

k: Tensor

nk x n_dim wave vectors

k_division: TaskDivision

Division of k-points over MPI

k_mine: slice

slice of k on current process

n_bands: int

number of bands at each k

n_dim: int

dimensionality of material (2 or 3)

rho0: Tensor

nk x n_bands x n_bands initial density matrix

property transport_velocity: Tensor

Effective velocity for each density-matrix component. This always has dimensions (nk_mine * (n_bands**2)) x 2.

v: Tensor

nk x n_bands x n_dim velocities in plane

wk: float

Brillouin zone integration weight