paulie.application.second_moment.second_moment#

paulie.application.second_moment.second_moment(operator_m, system_generators)#

Computes the second-order twirl of an operator \(M\) by projecting it onto the subspace of quadratic symmetries of a DLA.

Parameters:
  • operator_m (PauliStringLinear) – An operator \(M\) expressed as a linear combination of Pauli strings.

  • system_generators (PauliStringCollection) – Generating set of the Pauli string DLA.

Returns:

The second-order twirl of the operator \(M\).

Return type:

PauliStringLinear