Operator

class Operator(data, input_dims=None, output_dims=None)

Bases: qiskit.quantum_info.operators.linear_op.LinearOp

Matrix operator class

This represents a matrix operator \(M\) that will evolve() a Statevector \(|\psi\rangle\) by matrix-vector multiplication

\[|\psi\rangle \mapsto M|\psi\rangle,\]

and will evolve() a DensityMatrix \(\rho\) by left and right multiplication

\[\rho \mapsto M \rho M^\dagger.\]

Initialize an operator object.

Parameters

• (QuantumCircuit or (data) – Instruction or BaseOperator or matrix): data to initialize operator.

• input_dims (tuple) – the input subsystem dimensions. [Default: None]

• output_dims (tuple) – the output subsystem dimensions. [Default: None]

Raises

QiskitError – if input data cannot be initialized as an operator.

Additional Information:

If the input or output dimensions are None, they will be automatically determined from the input data. If the input data is a Numpy array of shape (2**N, 2**N) qubit systems will be used. If the input operator is not an N-qubit operator, it will assign a single subsystem with dimension specified by the shape of the input.

Methods

adjoint	Return the adjoint of the Operator.
compose	Return the operator composition with another Operator.
conjugate	Return the conjugate of the Operator.
copy	Make a deep copy of current operator.
dot	Return the right multiplied operator self * other.
equiv	Return True if operators are equivalent up to global phase.
expand	Return the reverse-order tensor product with another Operator.
from_label	Return a tensor product of single-qubit operators.
input_dims	Return tuple of input dimension for specified subsystems.
is_unitary	Return True if operator is a unitary matrix.
output_dims	Return tuple of output dimension for specified subsystems.
power	Return the matrix power of the operator.
reshape	Return a shallow copy with reshaped input and output subsystem dimensions.
reverse_qargs	Return an Operator with reversed subsystem ordering.
tensor	Return the tensor product with another Operator.
to_instruction	Convert to a UnitaryGate instruction.
to_operator	Convert operator to matrix operator class
transpose	Return the transpose of the Operator.

Attributes

atol = 1e-08

data

Return data.

dim

Return tuple (input_shape, output_shape).

num_qubits

Return the number of qubits if a N-qubit operator or None otherwise.

qargs

Return the qargs for the operator.

rtol = 1e-05

settings

Return operator settings.