Engineering reflective intelligence surface with ising hamiltonian and quantum annealing

Over the last few years, we have witnessed a growing interest in leveraging reconfigurable intelligence surfaces (RISs) towards smart wireless environments. One key question arises on how to efficiently select the phase/amplitude configuration of RIS in order to achieve a specific reflective and transmissive behavior. This is of paramount importance when a solution to the optimization problem is not available in closed-form, and thus constitutes a substantial computational task. In this paper, we propose to find the optimal phase configuration by a physics-based approach inspired by the quantum mechanical physics of spins. The values of the local reflection phases across the RIS are obtained by computing the ground state of the equivalent Hamiltonian on a quantum adiabatic optimizer machine. We believe the proposed work provides an interesting direction on the fast optimization of RISs for multi-beam generation in and beyond 5G/6G mobile networks.