A semiconductor integrated circuit includes an external pad, a ground line, a first protection circuit between the external pad and the ground line, and a second protection circuit between the external pad and the ground line. This provide an efficient scheme for linear optics quantum processing which is deterministic and for which qubit readout can use homodyne detection which is highly efficient. The sequence of deposition, etching, and deposition permits features with high aspect ratios to be filled, while the continuity of the process results in improved uniformity. Furthermore, the specular control device may prevent the specularly reflected light from reaching the spectroscopic analyzer. This oxidation reaction generates heat that heats up the fuel cell stack and the system. When the stop of the power supply is detected, a stop signal outputting circuit outputs a communication stop signal to said another data communication apparatus.