We experimentally study a Stub photonic lattice and excite their localized<br />
linear states originated from an isolated Flat Band at the center of the linear<br />
spectrum. By exciting these modes in different regions of the lattice, we<br />
observe that they do not diffract across the system and remain well trapped<br />
after propagating along the crystal. By using their wave nature, we are able to<br />
combine -- in phase and out of phase -- two neighbor states into a coherent<br />
superposition. These observations allow us to propose a novel setup for<br />
performing three different all-optical logical operations such as OR, AND, and<br />
XOR, positioning Flat Band systems as key setups to perform concrete<br />
applications at any level of power.