field.Field

field.Field(
    label='',
    index=0,
    coupled_levels=None,
    factors=None,
    detuning=0.0,
    detuning_positive=True,
    counter_propagating=False,
    factor_doppler_shift=None,
    rabi_freq=1.0,
    rabi_freq_t_func=None,
    rabi_freq_t_args=None,
)

Field object to address the OBAtom object, describing the atomic levels coupled, detuning and Rabi frequency function.

Attributes

Name	Type	Description
label	string	a name for the field e.g. “probe”.
index	int	index of the field, to reference within an OBAtom.
coupled_levels	list	pairs of levels coupled by the field. e.g. [[0,1], [0,2]]
factors	list	List of strength factors for each pair in coupled levels.
detuning	float	detuning of the fields from resonance with the coupled_levels transitions.
detuning_positive	bool	is the detuning positive?
counter_propagating	bool	if True, this field travels in the opposite direction to the forward-propagating solver direction. Sets factor_doppler_shift = -1.0. Orthogonal to detuning_positive.
factor_doppler_shift	float	multiplier applied to the thermal detuning Delta for each velocity class. Default 1.0 (co-propagating). Set to -1.0 for a counter-propagating field, or to an arbitrary float for schemes where wavelength differences matter (e.g. a three-photon ladder where k-vector magnitudes differ).
rabi_freq	float	Rabi frequency of the field on the transition.
rabi_freq_t_func	func	Time-dependency of rabi_freq as function of time f(t, args)
rabi_freq_t_args	dict	arguments to be passed to rabi_freq_t_func.

Methods

Name	Description
get_json_dict	Return a dict representation of the Field object to be dumped to
lower_levels	Return the unique lower (ground) level indices coupled by this field.
to_json_str	Return a JSON string representation of the Field object.
upper_levels	Return the unique upper (excited) level indices coupled by this field.

get_json_dict

field.Field.get_json_dict()

Return a dict representation of the Field object to be dumped to JSON.

Note

For the rabi_freq_t_func attribute generated with build_rabi_freq_t_func, a suffix for the index will have been added. We remove that. e.g. e.g. ramp_onoff_0 -> ramp_onoff

lower_levels

field.Field.lower_levels()

Return the unique lower (ground) level indices coupled by this field.

Returns

Name	Type	Description
	list[int]	Sorted list of unique indices c[0] from coupled_levels.

to_json_str

field.Field.to_json_str()

Return a JSON string representation of the Field object.

Returns

Name	Type	Description
	str	(string) JSON representation of the Field object.

upper_levels

field.Field.upper_levels()

Return the unique upper (excited) level indices coupled by this field.

Returns

Name	Type	Description
	list[int]	Sorted list of unique indices c[1] from coupled_levels.