qat.fermion.circuits.make_mrep_circ

qat.fermion.circuits.make_mrep_circ(n_fsim_cycles: int | None = 4, set_phi_to_0: bool | None = False) → Circuit

Constructs the 8-qubit Multi-Reference Excitation Preserving (MREP) ansatz that combines the multi-reference routine of Sugisaki et al. article (2019) with some fSim nearest-neighbour cycles. The second angles of the fSim gates (phi) may be taken to 0.

Parameters:

• n_fsim_cycles (int, optional) – Number of fSim cycles, defaults to 4.

• set_phi_to_0 (bool, optional) – Whether to set all second angles in the fSim gates to 0 (True) or not (False). Defaults to False.

Returns:

Circuit