Measurement#

This section covers the API reference for obtaining the expectation value of some (molecular) Hamiltonian

qibochem.measurement.expectation.expectation(circuit: Circuit, hamiltonian: SymbolicHamiltonian, from_samples=False, n_shots=1000) → float#

Calculate expectation value of some Hamiltonian using either the state vector or sample measurements from running a quantum circuit

Parameters:

  • circuit (qibo.models.Circuit) – Quantum circuit ansatz

  • hamiltonian (SymbolicHamiltonian) – Molecular Hamiltonian

  • from_samples (Boolean) – Whether the expectation value calculation uses samples or the simulated state vector. Default: False; Results are from a state vector simulation

  • n_shots (int) – Number of times the circuit is run if from_samples=True. Default: 1000

Returns:

Hamiltonian expectation value (float)