qiskit.opflow.primitive_ops.PauliOp

class PauliOp(primitive, coeff=1.0)

Class for Operators backed by Terra’s Pauli module.

Paramètres

• primitive (Pauli) – The Pauli which defines the behavior of the underlying function.

• coeff (Union[complex, ParameterExpression]) – A coefficient multiplying the primitive.

Lève

TypeError – invalid parameters.

__init__(primitive, coeff=1.0)

Paramètres

• primitive (Pauli) – The Pauli which defines the behavior of the underlying function.

• coeff (Union[complex, ParameterExpression]) – A coefficient multiplying the primitive.

Lève

TypeError – invalid parameters.

Methods

__init__(primitive[, coeff])	type primitive Pauli
add(other)	Return Operator addition of self and other, overloaded by +.
adjoint()	Return a new Operator equal to the Operator’s adjoint (conjugate transpose), overloaded by ~.
assign_parameters(param_dict)	Binds scalar values to any Terra Parameters in the coefficients or primitives of the Operator, or substitutes one Parameter for another.
bind_parameters(param_dict)	Same as assign_parameters, but maintained for consistency with QuantumCircuit in Terra (which has both assign_parameters and bind_parameters).
compose(other[, permutation, front])	Return Operator Composition between self and other (linear algebra-style: A@B(x) = A(B(x))), overloaded by @.
copy()	Return a deep copy of the Operator.
equals(other)	Evaluate Equality between Operators, overloaded by ==.
eval([front])	Evaluate the Operator’s underlying function, either on a binary string or another Operator.
exp_i()	Return a CircuitOp equivalent to e^-iH for this operator H.
log_i([massive])	Return a MatrixOp equivalent to log(H)/-i for this operator H.
mul(scalar)	Returns the scalar multiplication of the Operator, overloaded by *, including support for Terra’s Parameters, which can be bound to values later (via bind_parameters).
neg()	Return the Operator’s negation, effectively just multiplying by -1.0, overloaded by -.
permute(permutation)	Permutes the sequence of Pauli matrices.
power(exponent)	Return Operator composed with self multiple times, overloaded by **.
primitive_strings()	Return a set of strings describing the primitives contained in the Operator.
reduce()	Try collapsing the Operator structure, usually after some type of conversion, e.g.
tensor(other)	Return tensor product between self and other, overloaded by ^.
tensorpower(other)	Return tensor product with self multiple times, overloaded by ^.
to_circuit()	Returns a QuantumCircuit equivalent to this Operator.
to_circuit_op()	Returns a CircuitOp equivalent to this Operator.
to_instruction()	Returns an Instruction equivalent to this Operator.
to_matrix([massive])	Return NumPy representation of the Operator.
to_matrix_op([massive])	Returns a MatrixOp equivalent to this Operator.
to_pauli_op([massive])	Returns a sum of PauliOp s equivalent to this Operator.
to_spmatrix()	Returns SciPy sparse matrix representation of the Operator.

Attributes

INDENTATION
coeff	The scalar coefficient multiplying the Operator.
instance_id	Return the unique instance id.
num_qubits	The number of qubits over which the Operator is defined.
parameters	Return a set of Parameter objects contained in the Operator.
primitive	The primitive defining the underlying function of the Operator.

add(other)

Return Operator addition of self and other, overloaded by +.

Paramètres

other (OperatorBase) – An OperatorBase with the same number of qubits as self, and in the same “Operator”, “State function”, or “Measurement” category as self (i.e. the same type of underlying function).

Type renvoyé

OperatorBase

Renvoie

An OperatorBase equivalent to the sum of self and other.

adjoint()

Return a new Operator equal to the Operator’s adjoint (conjugate transpose), overloaded by ~. For StateFns, this also turns the StateFn into a measurement.

Type renvoyé

PauliOp

Renvoie

An OperatorBase equivalent to the adjoint of self.

assign_parameters(param_dict)

Binds scalar values to any Terra Parameters in the coefficients or primitives of the Operator, or substitutes one Parameter for another. This method differs from Terra’s assign_parameters in that it also supports lists of values to assign for a give Parameter, in which case self will be copied for each parameterization in the binding list(s), and all the copies will be returned in an OpList. If lists of parameterizations are used, every Parameter in the param_dict must have the same length list of parameterizations.

Paramètres

param_dict (dict) – The dictionary of Parameters to replace, and values or lists of values by which to replace them.

Type renvoyé

OperatorBase

Renvoie

The OperatorBase with the Parameters in self replaced by the values or Parameters in param_dict. If param_dict contains parameterization lists, this OperatorBase is an OpList.

bind_parameters(param_dict)

Same as assign_parameters, but maintained for consistency with QuantumCircuit in Terra (which has both assign_parameters and bind_parameters).

Type renvoyé

OperatorBase

property coeff

The scalar coefficient multiplying the Operator.

Type renvoyé

Union[complex, ParameterExpression]

Renvoie

The coefficient.

compose(other, permutation=None, front=False)

Return Operator Composition between self and other (linear algebra-style: A@B(x) = A(B(x))), overloaded by @.

Note: You must be conscious of Quantum Circuit vs. Linear Algebra ordering conventions. Meaning, X.compose(Y) produces an X∘Y on qubit 0, but would produce a QuantumCircuit which looks like

-[Y]-[X]-

Because Terra prints circuits with the initial state at the left side of the circuit.

Paramètres

• other (OperatorBase) – The OperatorBase with which to compose self.

• permutation (Optional[List[int]]) – List[int] which defines permutation on other operator.

• front (bool) – If front==True, return other.compose(self).

Type renvoyé

OperatorBase

Renvoie

An OperatorBase equivalent to the function composition of self and other.

copy()

Return a deep copy of the Operator.

Type renvoyé

OperatorBase

equals(other)

Evaluate Equality between Operators, overloaded by ==. Only returns True if self and other are of the same representation (e.g. a DictStateFn and CircuitStateFn will never be equal, even if their vector representations are equal), their underlying primitives are equal (this means for ListOps, OperatorStateFns, or EvolvedOps the equality is evaluated recursively downwards), and their coefficients are equal.

Paramètres

other (OperatorBase) – The OperatorBase to compare to self.

Type renvoyé

bool

Renvoie

A bool equal to the equality of self and other.

eval(front=None)

Evaluate the Operator’s underlying function, either on a binary string or another Operator. A square binary Operator can be defined as a function taking a binary function to another binary function. This method returns the value of that function for a given StateFn or binary string. For example, op.eval('0110').eval('1110') can be seen as querying the Operator’s matrix representation by row 6 and column 14, and will return the complex value at those « indices. » Similarly for a StateFn, op.eval('1011') will return the complex value at row 11 of the vector representation of the StateFn, as all StateFns are defined to be evaluated from Zero implicitly (i.e. it is as if .eval('0000') is already called implicitly to always « indexing » from column 0).

If front is None, the matrix-representation of the operator is returned.

Paramètres

front (Union[str, Dict[str, complex], ndarray, OperatorBase, Statevector, None]) – The bitstring, dict of bitstrings (with values being coefficients), or StateFn to evaluated by the Operator’s underlying function, or None.

Type renvoyé

Union[OperatorBase, complex]

Renvoie

The output of the Operator’s evaluation function. If self is a StateFn, the result is a float or complex. If self is an Operator (PrimitiveOp, ComposedOp, SummedOp, EvolvedOp, etc.), the result is a StateFn. If front is None, the matrix-representation of the operator is returned, which is a MatrixOp for the operators and a VectorStateFn for state-functions. If either self or front contain proper ListOps (not ListOp subclasses), the result is an n-dimensional list of complex or StateFn results, resulting from the recursive evaluation by each OperatorBase in the ListOps.

exp_i()

Return a CircuitOp equivalent to e^-iH for this operator H.

Type renvoyé

OperatorBase

property instance_id

Return the unique instance id.

Type renvoyé

int

log_i(massive=False)

Return a MatrixOp equivalent to log(H)/-i for this operator H. This function is the effective inverse of exp_i, equivalent to finding the Hermitian Operator which produces self when exponentiated.

Type renvoyé

OperatorBase

mul(scalar)

Returns the scalar multiplication of the Operator, overloaded by *, including support for Terra’s Parameters, which can be bound to values later (via bind_parameters).

Paramètres

scalar (Union[complex, ParameterExpression]) – The real or complex scalar by which to multiply the Operator, or the ParameterExpression to serve as a placeholder for a scalar factor.

Type renvoyé

OperatorBase

Renvoie

An OperatorBase equivalent to product of self and scalar.

neg()

Return the Operator’s negation, effectively just multiplying by -1.0, overloaded by -.

Type renvoyé

OperatorBase

Renvoie

An OperatorBase equivalent to the negation of self.

property num_qubits

The number of qubits over which the Operator is defined. If op.num_qubits == 5, then op.eval('1' * 5) will be valid, but op.eval('11') will not.

Type renvoyé

int

Renvoie

The number of qubits accepted by the Operator’s underlying function.

property parameters

Return a set of Parameter objects contained in the Operator.

permute(permutation)

Permutes the sequence of Pauli matrices.

Paramètres

permutation (List[int]) – A list defining where each Pauli should be permuted. The Pauli at index j of the primitive should be permuted to position permutation[j].

Type renvoyé

PauliOp

Renvoie

A new PauliOp representing the permuted operator. For operator (X ^ Y ^ Z) and indices=[1,2,4], it returns (X ^ I ^ Y ^ Z ^ I).

Lève

OpflowError – if indices do not define a new index for each qubit.

power(exponent)

Return Operator composed with self multiple times, overloaded by **.

Paramètres

exponent (int) – The int number of times to compose self with itself.

Type renvoyé

OperatorBase

Renvoie

An OperatorBase equivalent to self composed with itself exponent times.

property primitive

The primitive defining the underlying function of the Operator.

Type renvoyé

Union[QuantumCircuit, Operator, Pauli, SparsePauliOp, OperatorBase]

Renvoie

The primitive object.

primitive_strings()

Return a set of strings describing the primitives contained in the Operator. For example, {'QuantumCircuit', 'Pauli'}. For hierarchical Operators, such as ListOps, this can help illuminate the primitives represented in the various recursive levels, and therefore which conversions can be applied.

Type renvoyé

Set[str]

Renvoie

A set of strings describing the primitives contained within the Operator.

reduce()

Try collapsing the Operator structure, usually after some type of conversion, e.g. trying to add Operators in a SummedOp or delete needless IGates in a CircuitOp. If no reduction is available, just returns self.

Type renvoyé

OperatorBase

Renvoie

The reduced OperatorBase.

tensor(other)

Return tensor product between self and other, overloaded by ^. Note: You must be conscious of Qiskit’s big-endian bit printing convention. Meaning, X.tensor(Y) produces an X on qubit 0 and an Y on qubit 1, or X⨂Y, but would produce a QuantumCircuit which looks like

-[Y]- -[X]-

Because Terra prints circuits and results with qubit 0 at the end of the string or circuit.

Paramètres

other (OperatorBase) – The OperatorBase to tensor product with self.

Type renvoyé

OperatorBase

Renvoie

An OperatorBase equivalent to the tensor product of self and other.

tensorpower(other)

Return tensor product with self multiple times, overloaded by ^.

Paramètres

other (int) – The int number of times to tensor product self with itself via tensorpower.

Type renvoyé

Union[OperatorBase, int]

Renvoie

An OperatorBase equivalent to the tensorpower of self by other.

to_circuit()

Returns a QuantumCircuit equivalent to this Operator.

Type renvoyé

QuantumCircuit

to_circuit_op()

Returns a CircuitOp equivalent to this Operator.

Type renvoyé

OperatorBase

to_instruction()

Returns an Instruction equivalent to this Operator.

Type renvoyé

Instruction

to_matrix(massive=False)

Return NumPy representation of the Operator. Represents the evaluation of the Operator’s underlying function on every combination of basis binary strings. Warn if more than 16 qubits to force having to set massive=True if such a large vector is desired.

Type renvoyé

ndarray

Renvoie

The NumPy ndarray equivalent to this Operator.

to_matrix_op(massive=False)

Returns a MatrixOp equivalent to this Operator.

Type renvoyé

OperatorBase

to_pauli_op(massive=False)

Returns a sum of PauliOp s equivalent to this Operator.

Type renvoyé

PauliOp

to_spmatrix()

Returns SciPy sparse matrix representation of the Operator.

Type renvoyé

spmatrix

Renvoie

CSR sparse matrix representation of the Operator.

Lève

ValueError – invalid parameters.