Fig. 1.

QAOA protocol. The system is initialized along the $y$ direction in the Bloch sphere in the ${\left|+\right.⟩}^{\otimes N}$ state. The unitary evolution under $H_{A\left(B\right)}$ is implemented for angles ${\gamma }_i\left({\beta }_i\right)$ for $p$ times. At the end of the algorithm, global measurements in the $x$ and the $y$ basis are performed to compute the average energy $⟨H⟩=E\left(\overrightarrow{\beta },\overrightarrow{\gamma }\right)$, which is compared to the theoretical ground-state energy $E_{gs}$.