ob_solve.OBSolve

ob_solve.OBSolve(
    atom=None,
    t_min=0.0,
    t_max=1.0,
    t_steps=100,
    method='mesolve',
    opts=None,
    savefile=None,
)

Time-domain master equation solver for a single spatial point.

Wraps :func:qutip.mesolve to evolve an atomic density matrix described by an :class:~clerq.ob_atom.OBAtom over a user-defined time grid. Supports Doppler broadening via velocity classes and can save/load results to avoid recomputation.

Parameters

Name	Type	Description	Default
atom	dict | None	Dict (or empty dict for defaults) describing the atomic system; passed to :class:~clerq.ob_atom.OBAtom.	None
t_min	float	Start time of the simulation.	0.0
t_max	float	End time of the simulation.	1.0
t_steps	int	Number of time steps.	100
method	str	Solver method — 'mesolve' (Lindblad master equation) is the only supported value.	'mesolve'
opts	dict | None	Dict of QuTiP solver options passed to qutip.Options.	None
savefile	str | None	Path prefix for caching solved results ('.qu' extension appended automatically). Pass None to disable caching.	None

Methods

Name	Description
build_opts	Build the options dict to be passed into the QuTiP solver.
from_json	Initialise OBSolve from JSON file.
from_json_str	Initialise OBSolve from JSON string.
savefile_exists	Returns true if savefile (with appended extension .qu) exists.
set_field_rabi_freq_t_args	Set the Rabi frequency time function arguments. To be used with
set_field_rabi_freq_t_func	Set the Rabi frequency time function of a field to a new time

build_opts

ob_solve.OBSolve.build_opts(opts=None)

Build the options dict to be passed into the QuTiP solver.

Any option available to the QuTiP solver is available here, we provide defaults for solving the optical Bloch equations. See 0 for details of all the available options.

Notes

• For a stiff problem, it may help to set ‘method’ to ‘bdf’ instead of ‘adams’.
• If the solver times out, try more ‘nsteps’, though this will take longer.
• To speed up the solver, reduce atol and rtol, though this will reduce accuracy.

Warning

There is no validation checking here. If you pass in an option which is not known to QuTiP it will throw an exception.

from_json

ob_solve.OBSolve.from_json(file_path)

Initialise OBSolve from JSON file.

from_json_str

ob_solve.OBSolve.from_json_str(json_str)

Initialise OBSolve from JSON string.

savefile_exists

ob_solve.OBSolve.savefile_exists()

Returns true if savefile (with appended extension .qu) exists.

set_field_rabi_freq_t_args

ob_solve.OBSolve.set_field_rabi_freq_t_args(field_idx, t_args)

Set the Rabi frequency time function arguments. To be used with set_field_rabi_freq_t_func

Parameters

Name	Type	Description	Default
field_idx	int	The field for which to set the Rabi frequency t_args	required
t_args	dict	A dict representing the args to go with the t_func.	required

set_field_rabi_freq_t_func

ob_solve.OBSolve.set_field_rabi_freq_t_func(field_idx, t_func)

Set the Rabi frequency time function of a field to a new time function. This is useful when you want to set a custom function, not one available in t_funcs.py

Parameters

Name	Type	Description	Default
field_idx	int	The field for which to set the Rabi frequency t_func	required
t_func	Any	Rabi frequency as a function of time, f(t, args)	required