ffsim.qiskit.final_state_vector

ffsim.qiskit.final_state_vector(circuit, norb=None, nelec=None)[source]

Return the final state vector of a fermionic quantum circuit.

In a spinful circuit, spinless orbital rotation, fermionic FFT, Givens ansatz, diagonal Coulomb evolution, and UCJ gates may act on a single spin sector. Each such gate must act on all norb alpha qubits or all norb beta qubits, in ascending order.

Parameters:

  • norb (int | None) – The number of spatial orbitals.

  • nelec (int | tuple[int, int] | None) – Either a single integer representing the number of fermions for a spinless system, or a pair of integers storing the numbers of spin alpha and spin beta fermions.

  • circuit (QuantumCircuit) – The circuit composed of fermionic gates.

Return type:

StateVector

Returns:

The final state vector that results from applying the circuit to the vacuum state.