Double quantum dot systems offer a unique opportunity for studying the world of quantum transport, and are considered promising candidates for quantum information operations. This stems from the ability to localize an electron in a limited region in space on the dot, and monitor its presence and properties, through the rich Coulomb blockade behavior. This concept has been realized in a variety of material systems with controlled size and shape, down to a few nanometers scale. Another system, in which electrons can be stored and measured, is an electronic trap in solid. The electrons in such a trap are better isolated from the environment. However, their measurement and control are more difficult.

Here we demonstrate how these two systems, metallic double-dots and electronic traps, are combined to yield a hybrid structure in which an electron can be stored for long durations and can be easily detected and measured.

In this work, we investigate the dynamics of a single electron surface trap, embedded in a self-assembly metallic double-dot system. The charging and discharging of the trap by a single electron is manifested as a random telegraph signal (RTS) of the current through the double-dot device. We show that we can control the duration that an electron resides in the trap through the current, varying it between fractions of a second to minutes. Furthermore, we show that at the Coulomb blockade region, when no current is flowing, the electron can be kept in the trap for extremely long times (> hour).

We find significant similarities between the electrical RTS in the metallic nanoparticle system and the optical blinking, commonly observed and investigated in semiconductor quantum dots, suggesting that these are the optical and electrical manifestation of the same phenomenon.