VQE: minimise ⟨ψ(θ)|H|ψ(θ)⟩ over a parametric quantum circuit

Peruzzo-McClean-Shadbolt-Yung-Love-Aspuru-Guzik-O'Brien 2014 variational quantum eigensolver (VQE): a hybrid quantum-classical algorithm for approximating the ground-state energy of a Hamiltonian H. A parametrised quantum circuit U(θ)…