mindquantum.algorithm.nisq.get_reference_circuit

mindquantum.algorithm.nisq.get_reference_circuit(n_qubits: int, n_ele_alpha: Optional[int] = None, n_ele_beta: Optional[int] = None, ref: Union[AVA_REF, Iterable] = 'AllH')[source]

Get preparation circuit for reference circuit according to different methods.

The available methods are:

Method	Description
HF	Generate the Hartree-Fock (HF) reference state, where electrons occupy the lowest energy orbitals, suitable for Hartree-Fock (HF) orbitals.
Neel	Generate the Neel reference state, where electrons with different spins occupy adjacent orbitals, suitable for orthonormalized atomic orbitals.
Bell	Generate the tensor product of the Bell state as the reference state.
AllH	Generate the uniform superposition state as the reference state.

Parameters

n_qubits (int) – The total qubit number.
n_ele_alpha (int) – The number of alpha electrons. Default: None.
n_ele_beta (int) – The number of beta electrons. Default: None.
ref (Union[str, Iterable]) – The method to construct reference state. If it is a string, it should be one of 'HF', 'Neel', 'Bell', 'AllH'. Otherwise, it should be a iterator of int, and we place a RX gate on each qubit. Default: 'AllH'.

Examples

>>> from mindquantum.algorithm.nisq import get_reference_circuit
>>> get_reference_circuit(4, 1, 1, 'HF')
      ┏━━━┓
q0: ──┨╺╋╸┠─▓───
      ┗━━━┛ ▓
      ┏━━━┓ ▓
q1: ──┨╺╋╸┠─▓───
      ┗━━━┛ ▓
            ▓
q2: ────────▓───
            ▓
            ▓
q3: ────────▓───