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MCMTGate

class qiskit.circuit.library.MCMTGate(gate, num_ctrl_qubits, num_target_qubits, ctrl_state=None, label=None)

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Bases: ControlledGate

The multi-controlled multi-target gate, for an arbitrary singly controlled target gate.

For example, the H gate controlled on 3 qubits and acting on 2 target qubit is represented as:

───■────

───■────

───■────
┌──┴───┐
0
2-H │
1
└──────┘

Depending on the number of available auxiliary qubits, this operation can be synthesized using different methods. For example, if n1n - 1 clean auxiliary qubits are available (where nn is the number of control qubits), a V-chain decomposition can be used whose depth is linear in nn. See also synth_mcmt_chain().

Parameters

  • gate (Gate) – The base gate to apply on multiple target qubits, controlled by other qubits. This must be a single-qubit gate or a controlled single-qubit gate.
  • num_ctrl_qubits (int) – The number of control qubits.
  • num_target_qubits (int) – The number of target qubits.
  • ctrl_state (int |str | None) – The control state of the control qubits. Defaults to all closed controls.
  • label (str | None) – The gate label.

Attributes

base_class

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
True

In 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.

condition

The classical condition on the instruction.

Deprecated since version 1.3.0

The property qiskit.circuit.instruction.Instruction.condition is deprecated as of qiskit 1.3.0. It will be removed in 2.0.0.

condition_bits

Get Clbits in condition.

Deprecated since version 1.3.0

The property qiskit.circuit.instruction.Instruction.condition_bits is deprecated as of qiskit 1.3.0. It will be removed in 2.0.0.

ctrl_state

Return the control state of the gate as a decimal integer.

decompositions

Get the decompositions of the instruction from the SessionEquivalenceLibrary.

definition

Return definition in terms of other basic gates. If the gate has open controls, as determined from ctrl_state, the returned definition is conjugated with X without changing the internal _definition.

duration

Get the duration.

Deprecated since version 1.3.0

The property qiskit.circuit.instruction.Instruction.duration is deprecated as of qiskit 1.3.0. It will be removed in Qiskit 2.0.0.

label

Return instruction label

mutable

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

Get name of gate. If the gate has open controls the gate name will become:

<original_name_o<ctrl_state>

where <original_name> is the gate name for the default case of closed control qubits and <ctrl_state> is the integer value of the control state for the gate.

num_clbits

Return the number of clbits.

num_ctrl_qubits

Get number of control qubits.

Returns

The number of control qubits for the gate.

Return type

int

num_qubits

Return the number of qubits.

params

Get parameters from base_gate.

Returns

List of gate parameters.

Return type

list

Raises

CircuitError – Controlled gate does not define a base gate

unit

Get the time unit of duration.

Deprecated since version 1.3.0

The property qiskit.circuit.instruction.Instruction.unit is deprecated as of qiskit 1.3.0. It will be removed in Qiskit 2.0.0.


Methods

control

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

GitHub

Return the controlled version of the MCMT circuit.

inverse

inverse(annotated=False)

GitHub

Return the inverse MCMT circuit.

Parameters

annotated (bool) –

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