The technological achievements in electronics have been absolutely impressive over the course of the last decades with a major impact to the society that has drastically evolved towards the digital age. The fundamental principle behind this revolution is quite simple : the capability to open and close an electrical circuit as fast as possible in order to perform operation on a sequence of bits. In fact, modern electronic transistors can operate at frequencies well beyond 1 GHz, corresponding to 1 billion operations per second. However, the standard technological platform for obtaining these results is based on semiconductors like Silicon and has reached a bottleneck with objective difficulties in improving the speed at which electronic components work.

To overcome this limitation, an international collaboration involving researchers at the University of Luxembourg, at the University of Konstanz (Germany), at the CNRS-Université Paris-Saclay (France) and at the Donostia International Physics Center and CFM in San Sebastian (Spain), exploited light to control the motion of electrons in a metallic nanocircuit. The advantage of light is that it oscillates at frequencies that are a million times higher than the ones achieved by silicon electronics. For this reason, the control of a circuit at optical frequencies has the tremendous potential to revolutionize data processing and computing in the future.

While this goal is still far from being concrete, the experiments performed within this project proved that it is possible to use the single electric field oscillation contained in an ultrashort laser pulse to drive electrons within a nanoscopic gap of a circuit that otherwise would be open. The paper published in Nature Physics, contains a detailed description of the experiments and of the theoretical modeling devoted to understand how electrons move within this open gap between to metallic nanostructures.

The results of this work have a fundamental impact for the understanding on how light interacts with matter especially in a regime where it will be possible to observe quantum phenomena at temporal and spatial scales that were previously inaccessible. In addition, the impact of the research activity has also broad applications to nanotechnology, since special devices with high structural precision were fabricated for the experiments. As well as it has broad applications to laser science owing to the development of novel laser sources able to deliver extremely short pulses at high repetition rate.