ffsim.random.random_givens_ansatz_op

ffsim.random.random_givens_ansatz_op(norb, *, interaction_pairs=None, with_phis=True, with_phase_angles=True, seed=None)[source]

Sample a random Givens rotation ansatz operator.

The angles of the operator are sampled uniformly from the interval \([-\pi, \pi)\). The angles enter the operator as rotation angles and phases, so this window of width \(2 \pi\) samples them uniformly over their full period.

Parameters:

  • norb (int) – The number of spatial orbitals.

  • interaction_pairs (list[tuple[int, int]] | None) – The orbital pairs to apply the Givens rotations to. If not specified, a brickwork pattern of norb layers is used, which is enough to express an arbitrary orbital rotation.

  • with_phis (bool) – Whether to include complex phases for the Givens rotations.

  • with_phase_angles (bool) – Whether to include a layer of single-orbital phase gates.

  • seed – A seed to initialize the pseudorandom number generator. Should be a valid input to np.random.default_rng.

Return type:

GivensAnsatzOp

Returns:

The sampled Givens rotation ansatz operator.