UnitaryGate#

class qiskit.extensions.UnitaryGate(data, label=None)[source]#

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:

data (matrix or Operator) – unitary operator.
label (str) – unitary name for backend [Default: None].

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

adjoint()[source]#: Return the adjoint of the unitary.

assemble()#: Assemble a QasmQobjInstruction

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:

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

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[tuple[list, list]]

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()[source]#: Return the conjugate of the unitary.

control(num_ctrl_qubits=1, label=None, ctrl_state=None)[source]#

Return controlled version of gate

Parameters:

num_ctrl_qubits (int) – number of controls to add to gate (default=1)
label (str) – optional gate label
ctrl_state (int or str or None) – The control state in decimal or as a bit string (e.g. ‘1011’). If None, use 2**num_ctrl_qubits-1.

Returns:

controlled version of gate.

Return type:

UnitaryGate

Raises:

QiskitError – Invalid ctrl_state.
ExtensionError – Non-unitary controlled unitary.

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:: qiskit.circuit.Instruction

inverse()[source]#: Return the adjoint of the unitary.

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

power(exponent)#

Creates a unitary gate as gate^exponent.

Parameters:: exponent (float) – 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()#

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(n)#

Creates an instruction with gate repeated n amount of times.

Parameters:: n (int) – Number of times to repeat the instruction
Returns:: Containing the definition.
Return type:: qiskit.circuit.Instruction
Raises:: 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.

Returns:

a new instruction with: sub-instructions reversed.

Return type:

qiskit.circuit.Instruction

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

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()[source]#: Return the transpose of the unitary.

validate_parameter(parameter)[source]#: Unitary gate parameter has to be an ndarray.