CircuitRoutines

class scqubits.core.circuit_routines.CircuitRoutines

Methods

CircuitRoutines.__init__()
CircuitRoutines.create()
CircuitRoutines.cutoffs_dict()	Returns a dictionary, where each variable is associated with its respective cutoff.
CircuitRoutines.default_params()
CircuitRoutines.deserialize(io_data)
CircuitRoutines.discretized_grids_dict_for_vars()
CircuitRoutines.exp_i_operator(var_sym, ...)	Returns the bare operator exp(i* heta*prefactor), without the kron product.
CircuitRoutines.generate_bare_eigensys()	Returns the eigensystem of the Circuit, and all the subsystems involved in the bare basis.
CircuitRoutines.get_cutoffs()	Method to get the cutoffs for each of the circuit's degree of freedom.
CircuitRoutines.get_ext_basis()	Get the ext_basis object for the Circuit instance, according to the setting in self.hierarchical_diagonalization.
CircuitRoutines.get_operator_by_name(...[, ...])	Returns the operator for the given operator symbol which has the same dimension as the hilbertdim of the instance from which the operator is requested.
CircuitRoutines.get_osc_param(var_index[, ...])	Returns the oscillator parameters based on the oscillator used to diagonalize the Hamiltonian in the harmonic oscillator basis.
CircuitRoutines.get_subsystem_index(var_index)	Returns the subsystem index for the subsystem to which the given var_index belongs.
CircuitRoutines.hamiltonian()	Returns the Hamiltonian of the Circuit.
CircuitRoutines.hilbertdim()	Returns the Hilbert dimension of the Circuit instance.
CircuitRoutines.identity_wrap_for_hd(...[, ...])	Returns an identity wrapped operator whose size is equal to the self.hilbertdim().
CircuitRoutines.is_subsystem(instance)	Returns true if the instance is a subsystem of self (regardless of the hierarchy)
CircuitRoutines.offset_free_charge_values()	Returns all the offset charges set using the circuit attributes for each of the periodic degree of freedom.
CircuitRoutines.receive(event, sender, **kwargs)	Method to help the CentralDispatch keep track of the sync status in Circuit and SubSystem modules.
CircuitRoutines.return_parent_circuit()	Returns the parent Circuit instance.
CircuitRoutines.return_root_child(var_index)	Returns the root child of the subsystem instance with var_index in its dynamic_var_indices.
CircuitRoutines.serialize()
CircuitRoutines.set_and_return(attr_name, value)	Allows to set an attribute after which self is returned. This is useful for doing something like example::.
CircuitRoutines.set_bare_eigensys(eigensys)	Sets the bare eigensystem of the Circuit in the lookup table of hilbert_space attribute, if hierarchical diagonalization is used.
CircuitRoutines.set_discretized_phi_range(...)	Sets the flux range for discretized phi basis or for plotting.
CircuitRoutines.update([calculate_bare_esys])	Syncs all the parameters of the subsystems with the current instance.

cutoffs_dict()

Returns a dictionary, where each variable is associated with its respective cutoff.

Return type:

Dict[int, int]

Returns:

Cutoffs dictionary; {var_index: cutoff}

exp_i_operator(var_sym, prefactor)

Returns the bare operator exp(i* heta*prefactor), without the kron product.

Needs the oscillator lengths to be set in the attribute, osc_lengths, when ext_basis is set to “harmonic”.

Return type:

Union[csc_matrix, ndarray]

Parameters:

• var_sym (Symbol)

• prefactor (float)

generate_bare_eigensys()

Returns the eigensystem of the Circuit, and all the subsystems involved in the bare basis.

get_cutoffs()

Method to get the cutoffs for each of the circuit’s degree of freedom.

Return type:

Dict[str, list]

get_ext_basis()

Get the ext_basis object for the Circuit instance, according to the setting in self.hierarchical_diagonalization.

Return type:

Union[str, List[str]]

get_operator_by_name(operator_name, power=None, bare_esys=None)

Returns the operator for the given operator symbol which has the same dimension as the hilbertdim of the instance from which the operator is requested.

Parameters:

• operator_name (str) – Name of a sympy Symbol object which should be one among the symbols in the attribute vars

• power (Optional[int]) – If asking for an operator raised to a certain power. Which wen set to None defaults to 1

Return type:

Qobj

Returns:

operator identified by operator_name

get_osc_param(var_index, which_param='length')

Returns the oscillator parameters based on the oscillator used to diagonalize the Hamiltonian in the harmonic oscillator basis.

Parameters:

• var_index (int) – var index whose oscillator parameter needs to be fetched

• which_param (str) – “length” or “freq” - decides which parameter is returned, by default “length”

Return type:

float

Returns:

returns the float value which is the oscillator length or the frequency of the oscillator corresponding to var_index depending on the string which_param.

get_subsystem_index(var_index)

Returns the subsystem index for the subsystem to which the given var_index belongs.

Parameters:

var_index (int) – variable index in integer starting from 1.

Return type:

int

Returns:

subsystem index which can be used to identify the subsystem index in the list self.subsystems.

hamiltonian()

Returns the Hamiltonian of the Circuit.

Return type:

Union[csc_matrix, ndarray]

hilbertdim()

Returns the Hilbert dimension of the Circuit instance.

identity_wrap_for_hd(operator, child_instance, bare_esys=None)

Returns an identity wrapped operator whose size is equal to the self.hilbertdim(). Only converts operator which belongs to a specific variable index. For example, operator Q_1 or cos( heta_1). But not, Q1*Q2.

Parameters:

• operator (Union[csc_matrix, ndarray, None]) – operator in the form of csc_matrix, ndarray

• instance – The subsystem to which the operator belongs

• bare_esys (Optional[Dict[int, Tuple]]) – Dict containing subsystem indices starting from 0, paired with the bare esys for each of the subsystem

Return type:

Qobj

Returns:

identity wrapped operator.

is_subsystem(instance)

Returns true if the instance is a subsystem of self (regardless of the hierarchy)

offset_free_charge_values()

Returns all the offset charges set using the circuit attributes for each of the periodic degree of freedom.

Return type:

List[float]

receive(event, sender, **kwargs)

Method to help the CentralDispatch keep track of the sync status in Circuit and SubSystem modules.

Return type:

None

Parameters:

• event (str)

• sender (object)

return_parent_circuit()

Returns the parent Circuit instance.

return_root_child(var_index)

Returns the root child of the subsystem instance with var_index in its dynamic_var_indices.

Parameters:

var_index (int) – index of one of the dynamical degrees of freedom (from dynamic_var_indices)

Returns:

Subsystem instance with var_index in its dynamic_var_indices.

set_and_return(attr_name, value)

Allows to set an attribute after which self is returned. This is useful for doing something like example:

qubit.set_and_return('flux', 0.23).some_method()

instead of example:

qubit.flux=0.23
qubit.some_method()

Parameters:

• attr_name (str) – name of class attribute in string form

• value (Any) – value that the attribute is to be set to

Return type:

QubitBaseClass

Returns:

self

set_bare_eigensys(eigensys)

Sets the bare eigensystem of the Circuit in the lookup table of hilbert_space attribute, if hierarchical diagonalization is used.

set_discretized_phi_range(var_indices, phi_range)

Sets the flux range for discretized phi basis or for plotting.

Parameters:

• var_indices (Tuple[int]) – list of var_indices whose range needs to be changed

• phi_range (Tuple[float]) – The desired range for each of the discretized phi variables

Return type:

None

update(calculate_bare_esys=True)

Syncs all the parameters of the subsystems with the current instance.

Parameters:

calculate_bare_esys (bool)