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AnnotatedOperation

qiskit.circuit.AnnotatedOperation(base_op, modifiers)GitHub(opens in a new tab)

Bases: Operation

Annotated operation.

Create a new AnnotatedOperation.

An “annotated operation” allows to add a list of modifiers to the “base” operation. For now, the only supported modifiers are of types InverseModifier, ControlModifier and PowerModifier.

An annotated operation can be viewed as an extension of ControlledGate (which also allows adding control to the base operation). However, an important difference is that the circuit definition of an annotated operation is not constructed when the operation is declared, and instead happens during transpilation, specifically during the HighLevelSynthesis transpiler pass.

An annotated operation can be also viewed as a “higher-level” or “more abstract” object that can be added to a quantum circuit. This enables writing transpiler optimization passes that make use of this higher-level representation, for instance removing a gate that is immediately followed by its inverse.

Parameters

  • base_op (Operation) – base operation being modified
  • modifiers (Union[Modifier, List[Modifier]]) – ordered list of modifiers. Supported modifiers include InverseModifier, ControlModifier and PowerModifier.

Examples:

op1 = AnnotatedOperation(SGate(), [InverseModifier(), ControlModifier(2)])
 
op2_inner = AnnotatedGate(SGate(), InverseModifier())
op2 = AnnotatedGate(op2_inner, ControlModifier(2))

Both op1 and op2 are semantically equivalent to an SGate() which is first inverted and then controlled by 2 qubits.


Attributes

name

Unique string identifier for operation type.

num_clbits

Number of classical bits.

num_qubits

Number of qubits.


Methods

control

control(num_ctrl_qubits=1, label=None, ctrl_state=None, annotated=True)

Return the controlled version of itself.

Implemented as an annotated operation, see AnnotatedOperation.

Parameters

Returns

Controlled version of the given operation.

Return type

AnnotatedOperation

copy

copy()

Return a copy of the AnnotatedOperation.

Return type

AnnotatedOperation

inverse

inverse(annotated=True)

Return the inverse version of itself.

Implemented as an annotated operation, see AnnotatedOperation.

Parameters

annotated (bool(opens in a new tab)) – ignored (used for consistency with other inverse methods)

Returns

Inverse version of the given operation.

to_matrix

to_matrix()

Return a matrix representation (allowing to construct Operator).

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