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UnitaryGate

qiskit.extensions.UnitaryGate(data, label=None) GitHub(opens in a new tab)

Bases: Gate

Class quantum gates specified by a unitary matrix.

Example

We can create a unitary gate from a unitary matrix then add it to a quantum circuit. The matrix can also be directly applied to the quantum circuit, see QuantumCircuit.unitary().

from qiskit import QuantumCircuit
from qiskit.extensions import UnitaryGate
 
matrix = [[0, 0, 0, 1],
          [0, 0, 1, 0],
          [1, 0, 0, 0],
          [0, 1, 0, 0]]
gate = UnitaryGate(matrix)
 
circuit = QuantumCircuit(2)
circuit.append(gate, [0, 1])

Create a gate from a numeric unitary matrix.

Parameters

Raises

ExtensionError – if input data is not an N-qubit unitary operator.


Attributes

condition_bits

Get Clbits in condition.

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 instruction label

name

Return the name.

num_clbits

Return the number of clbits.

num_qubits

Return the number of qubits.

params

return instruction params.

unit

Get the time unit of duration.


Methods

add_decomposition

add_decomposition(decomposition)

Add a decomposition of the instruction to the SessionEquivalenceLibrary.

adjoint

adjoint()

Return the adjoint of the unitary.

assemble

assemble()

Assemble a QasmQobjInstruction

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

Iterable(opens in a new tab)[tuple(opens in a new tab)[list(opens in a new tab), list(opens in a new tab)]]

c_if

c_if(classical, val)

Set a classical equality condition on this instruction between the register or cbit classical and value val.

Note

This is a setter method, not an additive one. Calling this multiple times will silently override any previously set condition; it does not stack.

conjugate

conjugate()

Return the conjugate of the unitary.

control

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

Return controlled version of gate

Parameters

Returns

controlled version of gate.

Return type

UnitaryGate

Raises

copy

copy(name=None)

Copy of the instruction.

Parameters

name (str(opens in a new tab)) – 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

qiskit.circuit.Instruction

inverse

inverse()

Return the adjoint of the unitary.

is_parameterized

is_parameterized()

Return True .IFF. instruction is parameterized else False

power

power(exponent)

Creates a unitary gate as gate^exponent.

Parameters

exponent (float(opens in a new tab)) – Gate^exponent

Returns

To which to_matrix is self.to_matrix^exponent.

Return type

qiskit.extensions.UnitaryGate

Raises

CircuitError – If Gate is not unitary

qasm

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];).

Deprecated since version 0.25.0

The method qiskit.circuit.instruction.Instruction.qasm() is deprecated as of qiskit-terra 0.25.0. It will be removed no earlier than 3 months after the release date. Correct exporting to OpenQASM 2 is the responsibility of a larger exporter; it cannot safely be done on an object-by-object basis without context. No replacement will be provided, because the premise is wrong.

repeat

repeat(n)

Creates an instruction with gate repeated n amount of times.

Parameters

n (int(opens in a new tab)) – Number of times to repeat the instruction

Returns

Containing the definition.

Return type

qiskit.circuit.Instruction

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

qiskit.circuit.Instruction

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

bool(opens in a new tab)

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.

transpose

transpose()

Return the transpose of the unitary.

validate_parameter

validate_parameter(parameter)

Unitary gate parameter has to be an ndarray.

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