post_selection_transpiler_passes
qiskit_addon_utils.noise_management.post_selection.transpiler.passes
A submodule with transpilation passes for post selection.
AddSpectatorMeasures
class AddSpectatorMeasures(*args, **kwargs)
Bases: TransformationPass
Add measurements on spectator qubits.
An active qubit is a qubit acted on in the circuit by a non-barrier instruction. A terminated qubit is one whose last action is a measurement. A spectator qubit is a qubit that is inactive, but adjacent to an active qubit under the coupling map. This pass adds a measurement to all spectator qubits and, optionally via include_unmeasured, to all active qubits that are not terminated qubits.
The added measurements write to a new register that has one bit per spectator qubit and name spectator_creg_name.
When this pass encounters a control flow operation, it iterates through all of its blocks. It marks as “active” every qubit that is active within at least one of the blocks, and as “terminated” every qubit that is terminated in every one of the blocks.
Initialize the pass.
Parameters
- coupling_map – A coupling map or a list of tuples indicating pairs of neighboring qubits.
- include_unmeasured – Whether the qubits that are active but are not terminated by a measurement should also be treated as spectators. If
True, a terminal measurement is added on each of them. - spectator_creg_name – The name of the classical register added for the measurements on the spectator qubits.
- add_barrier – Whether to add a barrier acting on all active and spectator qubits prior to the spectator measurements.
execute
execute(passmanager_ir, state, callback=None)
Execute optimization task for input Qiskit IR.
Parameters
- passmanager_ir (Any) – Qiskit IR to optimize.
- state (PassManagerState) – State associated with workflow execution by the pass manager itself.
- callback (Callable | None) – A callback function which is caller per execution of optimization task.
Returns
Optimized Qiskit IR and state of the workflow.
Return type
is_analysis_pass
Check if the pass is an analysis pass.
If the pass is an AnalysisPass, that means that the pass can analyze the DAG and write the results of that analysis in the property set. Modifications on the DAG are not allowed by this kind of pass.
is_transformation_pass
Check if the pass is a transformation pass.
If the pass is a TransformationPass, that means that the pass can manipulate the DAG, but cannot modify the property set (but it can be read).
name
run
run(dag)
Run a pass on the DAGCircuit. This is implemented by the pass developer.
Parameters
dag (DAGCircuit) – the dag on which the pass is run.
Raises
NotImplementedError – when this is left unimplemented for a pass.
update_status
update_status(state, run_state)
Update workflow status.
Parameters
- state (PassManagerState) – Pass manager state to update.
- run_state (RunState) – Completion status of current task.
Returns
Updated pass manager state.
Return type
AddPostSelectionMeasures
class AddPostSelectionMeasures(*args, **kwargs)
Bases: TransformationPass
Add a post selection measurement after every terminal measurement.
A post selection measurement is a measurement that follows a regular measurement on a given qubit. It consists of a narrowband X-pulse followed by a regular measurement operation. In the absence of noise, it is expected to return (b + 1) % 2, where b is the outcome of the original measurement.
This pass adds post selection measurements after every terminal measurement, i.e., after every measurement that is not followed by another operation on the same wire. The added measurements are placed after a barrier, and write to new classical registers that are copies of the DAG’s registers, with modified names.
When this pass encounters a control flow operation, it iterates through all of its blocks. It marks as “terminated” only those qubits that are terminated in every one of the blocks, and it treats as unterminated every other qubit.
Initialize the pass.
Parameters
- x_pulse_type – The type of X-pulse to apply for the post-selection measurements.
- post_selection_suffix – A fixed suffix to append to the names of the classical registers when copying them.
execute
execute(passmanager_ir, state, callback=None)
Execute optimization task for input Qiskit IR.
Parameters
- passmanager_ir (Any) – Qiskit IR to optimize.
- state (PassManagerState) – State associated with workflow execution by the pass manager itself.
- callback (Callable | None) – A callback function which is caller per execution of optimization task.
Returns
Optimized Qiskit IR and state of the workflow.
Return type
is_analysis_pass
Check if the pass is an analysis pass.
If the pass is an AnalysisPass, that means that the pass can analyze the DAG and write the results of that analysis in the property set. Modifications on the DAG are not allowed by this kind of pass.
is_transformation_pass
Check if the pass is a transformation pass.
If the pass is a TransformationPass, that means that the pass can manipulate the DAG, but cannot modify the property set (but it can be read).
name
run
run(dag)
Run a pass on the DAGCircuit. This is implemented by the pass developer.
Parameters
dag (DAGCircuit) – the dag on which the pass is run.
Raises
NotImplementedError – when this is left unimplemented for a pass.
update_status
update_status(state, run_state)
Update workflow status.
Parameters
- state (PassManagerState) – Pass manager state to update.
- run_state (RunState) – Completion status of current task.
Returns
Updated pass manager state.
Return type
XSlowGate
class XSlowGate(label='xslow', xslow_gate_name='xslow')
Bases: Gate
The x-slow gate.
Parameters
- name – The name of the gate.
- num_qubits – The number of qubits the gate acts on.
- params – A list of parameters.
- label (str) – An optional label for the gate.
- xslow_gate_name (str)
add_decomposition
add_decomposition(decomposition)
Add a decomposition of the instruction to the SessionEquivalenceLibrary.
base_class
Type: Type[Instruction]
Get the base class of this instruction. This is guaranteed to be in the inheritance tree of self.
The “base class” of an instruction is the lowest class in its inheritance tree that the object should be considered entirely compatible with for _all_ circuit applications. This typically means that the subclass is defined purely to offer some sort of programmer convenience over the base class, and the base class is the “true” class for a behavioral perspective. In particular, you should not override base_class if you are defining a custom version of an instruction that will be implemented differently by hardware, such as an alternative measurement strategy, or a version of a parametrized gate with a particular set of parameters for the purposes of distinguishing it in a Target from the full parametrized gate.
This is often exactly equivalent to type(obj), except in the case of singleton instances of standard-library instructions. These singleton instances are special subclasses of their base class, and this property will return that base. For example:
>>> isinstance(XGate(), XGate)
True
>>> type(XGate()) is XGate
False
>>> XGate().base_class is XGate
TrueIn general, you should not rely on the precise class of an instruction; within a given circuit, it is expected that Instruction.name should be a more suitable discriminator in most situations.
broadcast_arguments
broadcast_arguments(qargs, cargs)
Validation and handling of the arguments and its relationship.
For example, cx([q[0],q[1]], q[2]) means cx(q[0], q[2]); cx(q[1], q[2]). This method yields the arguments in the right grouping. In the given example:
in: [[q[0],q[1]], q[2]],[]
outs: [q[0], q[2]], []
[q[1], q[2]], []The general broadcasting rules are:
If len(qargs) == 1:
[q[0], q[1]] -> [q[0]],[q[1]]If len(qargs) == 2:
[[q[0], q[1]], [r[0], r[1]]] -> [q[0], r[0]], [q[1], r[1]] [[q[0]], [r[0], r[1]]] -> [q[0], r[0]], [q[0], r[1]] [[q[0], q[1]], [r[0]]] -> [q[0], r[0]], [q[1], r[0]]If len(qargs) >= 3:
[q[0], q[1]], [r[0], r[1]], ...] -> [q[0], r[0], ...], [q[1], r[1], ...]
Parameters
Returns
A tuple with single arguments.
Raises
CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.
Return type
control
control(num_ctrl_qubits=1, label=None, ctrl_state=None, annotated=None)
Return the controlled version of itself.
Implemented either as a controlled gate (ref. ControlledGate) or as an annotated operation (ref. AnnotatedOperation).
Parameters
- num_ctrl_qubits (int) – number of controls to add to gate (default:
1) - label (str | None) – optional gate label. Ignored if implemented as an annotated operation.
- ctrl_state (int |str | None) – the control state in decimal or as a bitstring (e.g.
'111'). IfNone, use2**num_ctrl_qubits-1. - annotated (bool | None) – indicates whether the controlled gate is implemented as an annotated gate. If
None, this is set toFalseif the controlled gate can directly be constructed, and otherwise set toTrue. This allows defering the construction process in case the synthesis of the controlled gate requires more information (e.g. values of unbound parameters).
Returns
Controlled version of the given operation.
Raises
QiskitError – unrecognized mode or invalid ctrl_state
copy
copy(name=None)
Copy of the instruction.
Parameters
name (str) – name to be given to the copied circuit, if None then the name stays the same.
Returns
a copy of the current instruction, with the name updated if it was provided
Return type
decompositions
Get the decompositions of the instruction from the SessionEquivalenceLibrary.
definition
Return definition in terms of other basic gates.
inverse
inverse(annotated=False)
Invert this instruction.
If annotated is False, the inverse instruction is implemented as a fresh instruction with the recursively inverted definition.
If annotated is True, the inverse instruction is implemented as AnnotatedOperation, and corresponds to the given instruction annotated with the “inverse modifier”.
Special instructions inheriting from Instruction can implement their own inverse (e.g. T and Tdg, Barrier, etc.) In particular, they can choose how to handle the argument annotated which may include ignoring it and always returning a concrete gate class if the inverse is defined as a standard gate.
Parameters
annotated (bool) – if set to True the output inverse gate will be returned as AnnotatedOperation.
Returns
The inverse operation.
Raises
CircuitError – if the instruction is not composite and an inverse has not been implemented for it.
is_parameterized
is_parameterized()
Return whether the Instruction contains compile-time parameters.
label
Type: str
Return instruction label
mutable
Type: bool
Is this instance is a mutable unique instance or not.
If this attribute is False the gate instance is a shared singleton and is not mutable.
name
Return the name.
num_clbits
Return the number of clbits.
num_qubits
Return the number of qubits.
params
The parameters of this Instruction. Ideally these will be gate angles.
power
power(exponent, annotated=False)
Raise this gate to the power of exponent.
Implemented either as a unitary gate (ref. UnitaryGate) or as an annotated operation (ref. AnnotatedOperation). In the case of several standard gates, such as RXGate, when the power of a gate can be expressed in terms of another standard gate that is returned directly.
Parameters
- exponent (float) – the power to raise the gate to
- annotated (bool) – indicates whether the power gate can be implemented as an annotated operation. In the case of several standard gates, such as
RXGate, this argument is ignored when the power of a gate can be expressed in terms of another standard gate.
Returns
An operation implementing gate^exponent
Raises
CircuitError – If gate is not unitary
repeat
repeat(n)
Creates an instruction with self repeated :math`n` times.
Parameters
n (int) – Number of times to repeat the instruction
Returns
Containing the definition.
Return type
Raises
CircuitError – If n < 1.
reverse_ops
reverse_ops()
For a composite instruction, reverse the order of sub-instructions.
This is done by recursively reversing all sub-instructions. It does not invert any gate.
Returns
a new instruction with
sub-instructions reversed.
Return type
soft_compare
soft_compare(other)
Soft comparison between gates. Their names, number of qubits, and classical bit numbers must match. The number of parameters must match. Each parameter is compared. If one is a ParameterExpression then it is not taken into account.
Parameters
other (instruction) – other instruction.
Returns
are self and other equal up to parameter expressions.
Return type
to_matrix
to_matrix()
Return a Numpy.array for the gate unitary matrix.
Returns
if the Gate subclass has a matrix definition.
Return type
np.ndarray
Raises
CircuitError – If a Gate subclass does not implement this method an exception will be raised when this base class method is called.
to_mutable
to_mutable()
Return a mutable copy of this gate.
This method will return a new mutable copy of this gate instance. If a singleton instance is being used this will be a new unique instance that can be mutated. If the instance is already mutable it will be a deepcopy of that instance.
validate_parameter
validate_parameter(parameter)
Gate parameters should be int, float, or ParameterExpression