quri_parts.chem.utils.orbital_rotation module#

quri_parts.chem.utils.orbital_rotation.add_orbital_rotation_gate(circuit: LinearMappedUnboundParametricQuantumCircuit, qubit_indices: Sequence[int], param_fn: Parameter | Mapping[Parameter, float]) → LinearMappedUnboundParametricQuantumCircuit#

Add four-qubit spatial orbital rotation gate \(\textrm{QNP}_{\textrm{OR}}(\phi)\) that conserves the number of particles.

Ref.

Anselmetti et al., Local, expressive, quantum-number-preserving VQE ansätze for fermionic systems, 2021 New J. Phys. 23 113010, DOI 10.1088/1367-2630/ac2cb3

See also PennyLane’s documentations, qml.OrbitalRotation

Parameters:

  • circuit – LinearMappedUnboundParametricQuantumCircuit that the orbital rotation gate is added to.

  • phi – circuit‘s input parameter.

  • coeff – Parameter coefficient.

  • const – Constant for out_params of linear mapping.