# qiskit.quantum_info.Operator¶

class Operator(data, input_dims=None, output_dims=None)[소스]

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.

매개변수
• (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]

예외

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

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.

__init__(data, input_dims=None, output_dims=None)[소스]

Initialize an operator object.

매개변수
• (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]

예외

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

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

 __init__(data[, input_dims, output_dims]) Initialize an operator object. add(other) Return the linear operator self + other. Return the adjoint of the operator. compose(other[, qargs, front]) Return the composed operator. Return the conjugate of the operator. Make a deep copy of current operator. dot(other[, qargs]) Return the right multiplied operator self * other. equiv(other[, rtol, atol]) Return True if operators are equivalent up to global phase. expand(other) Return the tensor product operator other ⊗ self. from_label(label) Return a tensor product of single-qubit operators. input_dims([qargs]) Return tuple of input dimension for specified subsystems. is_unitary([atol, rtol]) Return True if operator is a unitary matrix. multiply(other) Return the linear operator other * self. output_dims([qargs]) Return tuple of output dimension for specified subsystems. Return the matrix power of the operator. reshape([input_dims, output_dims]) Return a shallow copy with reshaped input and output subsystem dimensions. set_atol(value) Set the class default absolute tolerance parameter for float comparisons. set_rtol(value) Set the class default relative tolerance parameter for float comparisons. subtract(other) Return the linear operator self - other. tensor(other) Return the tensor product operator self ⊗ other. Convert to a UnitaryGate instruction. Convert operator to matrix operator class Return the transpose of the operator.

Attributes

 atol The default absolute tolerance parameter for float comparisons. 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 The relative tolerance parameter for float comparisons.
add(other)

Return the linear operator self + other.

DEPRECATED: use operator + other instead.

매개변수

other (BaseOperator) – an operator object.

반환값

the operator self + other.

반환 형식

BaseOperator

adjoint()

Return the adjoint of the operator.

property atol

The default absolute tolerance parameter for float comparisons.

compose(other, qargs=None, front=False)[소스]

Return the composed operator.

매개변수
• other (Operator) – an operator object.

• qargs (list or None) – a list of subsystem positions to apply other on. If None apply on all subsystems [default: None].

• front (bool) – If True compose using right operator multiplication, instead of left multiplication [default: False].

반환값

The operator self @ other.

반환 형식

Operator

예외

QiskitError – if operators have incompatible dimensions for composition.

Composition (@) is defined as left matrix multiplication for matrix operators. That is that A @ B is equal to B * A. Setting front=True returns right matrix multiplication A * B and is equivalent to the dot() method.

conjugate()[소스]

Return the conjugate of the operator.

copy()

Make a deep copy of current operator.

property data

Return data.

property dim

Return tuple (input_shape, output_shape).

dot(other, qargs=None)[소스]

Return the right multiplied operator self * other.

매개변수
• other (Operator) – an operator object.

• qargs (list or None) – a list of subsystem positions to apply other on. If None apply on all subsystems [default: None].

반환값

The operator self * other.

반환 형식

Operator

예외

QiskitError – if other cannot be converted to an Operator or has incompatible dimensions.

equiv(other, rtol=None, atol=None)[소스]

Return True if operators are equivalent up to global phase.

매개변수
• other (Operator) – an operator object.

• rtol (float) – relative tolerance value for comparison.

• atol (float) – absolute tolerance value for comparison.

반환값

True if operators are equivalent up to global phase.

반환 형식

bool

expand(other)[소스]

Return the tensor product operator other ⊗ self.

매개변수

other (Operator) – an operator object.

반환값

the tensor product operator other ⊗ self.

반환 형식

Operator

예외

QiskitError – if other cannot be converted to an operator.

classmethod from_label(label)[소스]

Return a tensor product of single-qubit operators.

매개변수

label (string) – single-qubit operator string.

반환값

The N-qubit operator.

반환 형식

Operator

예외

QiskitError – if the label contains invalid characters, or the length of the label is larger than an explicitly specified num_qubits.

The labels correspond to the single-qubit matrices: 〈I〉: [[1, 0], [0, 1]] 〈X〉: [[0, 1], [1, 0]] 〈Y〉: [[0, -1j], [1j, 0]] 〈Z〉: [[1, 0], [0, -1]] 〈H〉: [[1, 1], [1, -1]] / sqrt(2) 〈S〉: [[1, 0], [0 , 1j]] 〈T〉: [[1, 0], [0, (1+1j) / sqrt(2)]] 〈0〉: [[1, 0], [0, 0]] 〈1〉: [[0, 0], [0, 1]] 〈+〉: [[0.5, 0.5], [0.5 , 0.5]] 〈-〈: [[0.5, -0.5], [-0.5 , 0.5]] 〈r〉: [[0.5, -0.5j], [0.5j , 0.5]] 〈l〉: [[0.5, 0.5j], [-0.5j , 0.5]]

input_dims(qargs=None)

Return tuple of input dimension for specified subsystems.

is_unitary(atol=None, rtol=None)[소스]

Return True if operator is a unitary matrix.

multiply(other)

Return the linear operator other * self.

DEPRECATED: use other * operator instead.

매개변수

other (complex) – a complex number.

반환값

the linear operator other * self.

반환 형식

BaseOperator

예외

NotImplementedError – if subclass does not support multiplication.

property num_qubits

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

output_dims(qargs=None)

Return tuple of output dimension for specified subsystems.

power(n)[소스]

Return the matrix power of the operator.

매개변수

n (int) – the power to raise the matrix to.

반환값

the n-times composed operator.

반환 형식

BaseOperator

예외

QiskitError – if the input and output dimensions of the operator are not equal, or the power is not a positive integer.

property qargs

Return the qargs for the operator.

reshape(input_dims=None, output_dims=None)

Return a shallow copy with reshaped input and output subsystem dimensions.

Arg:
input_dims (None or tuple): new subsystem input dimensions.

If None the original input dims will be preserved [Default: None].

output_dims (None or tuple): new subsystem output dimensions.

If None the original output dims will be preserved [Default: None].

반환값

returns self with reshaped input and output dimensions.

반환 형식

BaseOperator

예외

QiskitError – if combined size of all subsystem input dimension or subsystem output dimensions is not constant.

property rtol

The relative tolerance parameter for float comparisons.

classmethod set_atol(value)

Set the class default absolute tolerance parameter for float comparisons.

DEPRECATED: use operator.atol = value instead

classmethod set_rtol(value)

Set the class default relative tolerance parameter for float comparisons.

DEPRECATED: use operator.rtol = value instead

subtract(other)

Return the linear operator self - other.

DEPRECATED: use operator - other instead.

매개변수

other (BaseOperator) – an operator object.

반환값

the operator self - other.

반환 형식

BaseOperator

tensor(other)[소스]

Return the tensor product operator self ⊗ other.

매개변수

other (Operator) – a operator subclass object.

반환값

the tensor product operator self ⊗ other.

반환 형식

Operator

예외

QiskitError – if other cannot be converted to an operator.

to_instruction()[소스]

Convert to a UnitaryGate instruction.

to_operator()[소스]

Convert operator to matrix operator class

transpose()[소스]

Return the transpose of the operator.