Device with a detection structure with coulomb blockade superimposed on a quantum dot

A quantum device formed on a substrate and comprising:

• a first level wherein at least one semiconductor region is arranged,
• a second level wherein at least one first gate block is arranged and designed to modulate the potential of a quantum dot formed in the at least one semiconductor region, the second level further comprising a structure for detecting a state of charge of the quantum dot, said detection structure including a detection island disposed above and facing the quantum dot and able to be coupled to the quantum dot by capacitive coupling, said detection structure furthermore including at least one first tunnel junction between said detection island and the first gate block, said detection island and the first gate block being separated by a dielectric region, the first gate block being juxtaposed with said detection island, the first gate block being configured to form a reservoir of charges for the detection island.