qiskit.opflow.primitive_ops.Z2Symmetries

class Z2Symmetries(symmetries, sq_paulis, sq_list, tapering_values=None)

Z2 Symmetries

Parameters

• symmetries (List[Pauli]) – the list of Pauli objects representing the Z_2 symmetries

• sq_paulis (List[Pauli]) – the list of single - qubit Pauli objects to construct the Clifford operators

• sq_list (List[int]) – the list of support of the single-qubit Pauli objects used to build the Clifford operators

• tapering_values (Optional[List[int]]) – values determines the sector.

Raises

OpflowError – Invalid paulis

__init__(symmetries, sq_paulis, sq_list, tapering_values=None)

Parameters

• symmetries (List[Pauli]) – the list of Pauli objects representing the Z_2 symmetries

• sq_paulis (List[Pauli]) – the list of single - qubit Pauli objects to construct the Clifford operators

• sq_list (List[int]) – the list of support of the single-qubit Pauli objects used to build the Clifford operators

• tapering_values (Optional[List[int]]) – values determines the sector.

Raises

OpflowError – Invalid paulis

Methods

__init__(symmetries, sq_paulis, sq_list[, …])	type symmetries List[Pauli]
consistent_tapering(operator)	Tapering the operator with the same manner of how this tapered operator is created.
copy()	Get a copy of self.
find_Z2_symmetries(operator)	Finds Z2 Pauli-type symmetries of an Operator.
is_empty()	Check the z2_symmetries is empty or not.
taper(operator)	Taper an operator based on the z2_symmetries info and sector defined by tapering_values.

Attributes

cliffords	Get clifford operators, build based on symmetries and single-qubit X.
sq_list	returns sq list
sq_paulis	returns sq paulis
symmetries	return symmetries
tapering_values	returns tapering values

property cliffords

Get clifford operators, build based on symmetries and single-qubit X. :rtype: List[PauliSumOp] :returns: a list of unitaries used to diagonalize the Hamiltonian.

consistent_tapering(operator)

Tapering the operator with the same manner of how this tapered operator is created. i.e., using the same Cliffords and tapering values.

Parameters

operator (PauliSumOp) – the to-be-tapered operator

Return type

OperatorBase

Returns

The tapered operator

Raises

OpflowError – The given operator does not commute with the symmetry

copy()

Get a copy of self. :rtype: Z2Symmetries :returns: copy

classmethod find_Z2_symmetries(operator)

Finds Z2 Pauli-type symmetries of an Operator.

Return type

Z2Symmetries

Returns

a z2_symmetries object contains symmetries, single-qubit X, single-qubit list.

is_empty()

Check the z2_symmetries is empty or not. :rtype: bool :returns: Empty or not

property sq_list

returns sq list

property sq_paulis

returns sq paulis

property symmetries

return symmetries

taper(operator)

Taper an operator based on the z2_symmetries info and sector defined by tapering_values. The tapering_values will be stored into the resulted operator for a record.

Parameters

operator (PauliSumOp) – the to-be-tapered operator.

Returns

[:class`PauliSumOp`]; otherwise, PauliSumOp

Return type

If tapering_values is None

Raises

OpflowError – Z2 symmetries, single qubit pauli and single qubit list cannot be empty

property tapering_values

returns tapering values