qimpy.transport.material.Material

class Material(*, checkpoint_in=(None, ''))

Bases: TreeNode

Base class / interface for material specifications.

Parameters:: checkpoint_in (CheckpointPath)

__init__(*, checkpoint_in=(None, ''))

Parameters:: checkpoint_in (CheckpointPath)
Return type:: None

Methods

`__init__`
`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 list of observable names, 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).
`initialize`	Initialize shared material parameters (call from a derived class.)
`initialize_fields`	Initialize spatially-dependent / parameter sweep values.
`measure_observables`	Return expectation value of observables, (Nx x Ny x No).
`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
`nk_mine`	number of k-points 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_mine x n_dim wave vectors
`E`	nk_mine x n_bands energies
`v`	nk_mine x n_bands x n_dim velocities in plane
`rho0`	nk_mine x n_bands x n_bands initial density matrix
`dt_max`	maximum stable time-step (set to inf if not available)
`child_names`	Names of attributes with child objects.
`variant_name`	Version of children having variants (if any)

abstractmethod 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]

abstractmethod get_observable_names()

Return list of observable names, specific to each material.

Return type:: list[str]

abstractmethod get_observables(t)

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

Parameters:: t (float)
Return type:: Tensor

abstractmethod 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]

initialize(*, wk, nk, n_bands, n_dim, process_grid)

Initialize shared material parameters (call from a derived class.)

Parameters:

wk (float)
nk (int)
n_bands (int)
n_dim (int)
process_grid (ProcessGrid)

Return type:

None

abstractmethod initialize_fields(rho, params, patch_id)

Initialize spatially-dependent / parameter sweep values. Using named properties params, containing tensors that should broadcast with the grid dimensions, update the density matrix rho to be spatially varying if necessary and calculate any named fields for use during dynamics. Note that the cached quantities must be associated with patch_id, as there may be multiple spatial domains (patches) sharing the same material.

Parameters:

rho (Tensor)
params (dict[str, Tensor])
patch_id (int)

Return type:

None

measure_observables(rho, t)

Return expectation value of observables, (Nx x Ny x No).

Parameters:

rho (Tensor)
t (float)

Return type:

Tensor

abstractmethod rho_dot(rho, t, patch_id)

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

Parameters:

rho (Tensor)
t (float)
patch_id (int)

Return type:

Tensor

E: Tensor: nk_mine x n_bands energies

comm: Comm: Communicator for reciprocal-space split over k

dt_max: float: maximum stable time-step (set to inf if not available)

k: Tensor: nk_mine 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)

nk_mine: int: number of k-points on current process

rho0: Tensor: nk_mine 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_mine x n_bands x n_dim velocities in plane

wk: float: Brillouin zone integration weight