fastdla.SparsePauliSum

class fastdla.SparsePauliSum(indices, coeffs, num_qubits=None, no_check=False)

Purpose-specific implementation of a sparse Pauli operator.

SparsePauliSum is conceptually an array of ``PauliProduct``s with complex coefficients. Internally, the Pauli product indices and coefficients are stored separately as numpy arrays.

Parameters:

• indices (str | int | Sequence[str] | Sequence[Sequence[int]] | Sequence[int]) – A list of parameters, each of which can initialize a PauliProduct. A single integer or str is allowed, in which case a length-1 Pauli sum is initialized.

• coeffs (Number | Sequence[Number]) – Array of coefficients corresponding to the Pauli products specified by indices.

• num_qubits (Optional[int]) – Required if Pauli products are specified using the compact index.

• no_check (bool) – If True, indices is assumed to be an array of compact indices, and no formatting will be performed.

Methods

commutator(other[, normalize])	Return the commutator [self, other].
dot(other)	Return the inner product <self, other>.
from_csr(array, num_qubits)	Convert from a sparse Pauli vector in the CSR format.
normalize()	Return a normalized copy of this Pauli sum.
switch_impl(to)	Switch the implementation of operators.
to_csr()	Convert to a sparse Pauli vector in the CSR format.
to_dense()	Convert to a dense Pauli vector.
to_matrix(*[, sparse, npmod])	Convert the Pauli sum to a dense (2**num_qubits, 2**num_qubits) matrix.

Attributes

apart	Return a new SPS with anti-Hermitian terms only.
hpart	Return a new SPS with Hermitian terms only.
num_terms	Number of terms in the sum.
paulis	Return the list of PauliProducts in the string representation.
shape	Shape of the Pauli tensor.
vlen	Length of the Pauli vector.