qiskit.circuit.library.MCXGrayCode¶

class MCXGrayCode(num_ctrl_qubits=None, label=None, ctrl_state=None)[source]¶

Implement the multi-controlled X gate using the Gray code.

This delegates the implementation to the MCU1 gate, since \(X = H \cdot U1(\pi) \cdot H\).

Create new MCX gate.

__init__(num_ctrl_qubits, label=None, ctrl_state=None)[source]¶: Create new MCX gate.

Methods

`__init__`(num_ctrl_qubits[, label, ctrl_state])	Create new MCX gate.
`add_decomposition`(decomposition)	Add a decomposition of the instruction to the SessionEquivalenceLibrary.
`assemble`()	Assemble a QasmQobjInstruction
`broadcast_arguments`(qargs, cargs)	Validation and handling of the arguments and its relationship.
`c_if`(classical, val)	Add classical condition on register classical and value val.
`control`([num_ctrl_qubits, label, ctrl_state])	Return a multi-controlled-X gate with more control lines.
`copy`([name])	Copy of the instruction.
`get_num_ancilla_qubits`(num_ctrl_qubits[, mode])	Get the number of required ancilla qubits without instantiating the class.
`inverse`()	Invert this gate.
`is_parameterized`()	Return True .IFF.
`mirror`()	DEPRECATED: use instruction.reverse_ops().
`power`(exponent)	Creates a unitary gate as gate^exponent.
`qasm`()	Return a default OpenQASM string for the instruction.
`repeat`(n)	Creates an instruction with gate repeated n amount of times.
`reverse_ops`()	For a composite instruction, reverse the order of sub-instructions.
`to_matrix`()	Return a Numpy.array for the gate unitary matrix.
`validate_parameter`(parameter)	Gate parameters should be int, float, or ParameterExpression

Attributes

`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.
`duration`	Get the duration.
`label`	Return gate label
`num_ancilla_qubits`	The number of ancilla qubits.
`num_ctrl_qubits`	Get number of control qubits.
`params`	Get parameters from base_gate.
`unit`	Get the time unit of duration.

add_decomposition(decomposition)¶: Add a decomposition of the instruction to the SessionEquivalenceLibrary.

assemble()¶

Assemble a QasmQobjInstruction

Type renvoyé: Instruction

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], ...]

Paramètres

qargs (List) – List of quantum bit arguments.
cargs (List) – List of classical bit arguments.

Type renvoyé

Tuple[List, List]

Renvoie

A tuple with single arguments.

Lève

CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.

c_if(classical, val)¶: Add classical condition on register classical and value val.

control(num_ctrl_qubits=1, label=None, ctrl_state=None)¶

Return a multi-controlled-X gate with more control lines.

Paramètres

num_ctrl_qubits (int) – number of control qubits.
label (str or None) – An optional label for the gate [Default: None]
ctrl_state (int or str or None) – control state expressed as integer, string (e.g. “110”), or None. If None, use all 1s.

Renvoie

controlled version of this gate.

Type renvoyé

ControlledGate

copy(name=None)¶

Copy of the instruction.

Paramètres

name (str) – name to be given to the copied circuit, if None then the name stays the same.

Renvoie

a copy of the current instruction, with the name: updated if it was provided

Type renvoyé

qiskit.circuit.Instruction

property ctrl_state¶

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

Type renvoyé: int

property decompositions¶: Get the decompositions of the instruction from the SessionEquivalenceLibrary.

property definition¶

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

Type renvoyé: List

property duration¶: Get the duration.

static get_num_ancilla_qubits(num_ctrl_qubits, mode='noancilla')¶

Get the number of required ancilla qubits without instantiating the class.

This staticmethod might be necessary to check the number of ancillas before creating the gate, or to use the number of ancillas in the initialization.

inverse()[source]¶: Invert this gate. The MCX is its own inverse.

is_parameterized()¶: Return True .IFF. instruction is parameterized else False

property label¶

Return gate label

Type renvoyé: str

mirror()¶

DEPRECATED: use instruction.reverse_ops().

Renvoie

a new instruction with sub-instructions: reversed.

Type renvoyé

qiskit.circuit.Instruction

property num_ancilla_qubits¶: The number of ancilla qubits.

property num_ctrl_qubits¶

Get number of control qubits.

Renvoie: The number of control qubits for the gate.
Type renvoyé: int

property params¶

Get parameters from base_gate.

Renvoie: List of gate parameters.
Type renvoyé: list
Lève: CircuitError – Controlled gate does not define a base gate

power(exponent)¶

Creates a unitary gate as gate^exponent.

Paramètres: exponent (float) – Gate^exponent
Renvoie: To which to_matrix is self.to_matrix^exponent.
Type renvoyé: qiskit.extensions.UnitaryGate
Lève: CircuitError – If Gate is not unitary

qasm()¶

Return a default OpenQASM string for the instruction.

Derived instructions may override this to print in a different format (e.g. measure q[0] -> c[0];).

repeat(n)¶

Creates an instruction with gate repeated n amount of times.

Paramètres: n (int) – Number of times to repeat the instruction
Renvoie: Containing the definition.
Type renvoyé: qiskit.circuit.Instruction
Lève: CircuitError – If n < 1.

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.

Renvoie

a new instruction with: sub-instructions reversed.

Type renvoyé

qiskit.circuit.Instruction

to_matrix()¶

Return a Numpy.array for the gate unitary matrix.

Lève: CircuitError – If a Gate subclass does not implement this method an exception will be raised when this base class method is called.
Type renvoyé: ndarray

property unit¶: Get the time unit of duration.

validate_parameter(parameter)¶: Gate parameters should be int, float, or ParameterExpression