Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS


ELECTRONOPERA Sintesi della relazione

Project ID: 259141
Finanziato nell'ambito di: FP7-IDEAS-ERC
Paese: Sweden

Final Report Summary - ELECTRONOPERA (Electron dynamics to the Attosecond time scale and Angstrom length scale on low dimensional structures in Operation)

As we make smaller and smaller electronic devices, we approach unknown territory, where electrons will behave differently. The ability to image electrons on faster time scales and in smaller structures will enable us to "see" phenomena never observed before. We experience the consequences of electron motion and excitations all around us all the time. When we turn on the lights electrons are moved around, the transistors in our computers rely on moving electrons, and important future energy sources are based on excitations of electrons in a solar cell. In addition, the understanding of correlated electron structure in dynamic systems is still one of the unresolved challenges in modern physics. So it is both fascinating and of fundamental interest to directly “see” electrons, with a detail corresponding to an electron moving across the individual atoms, when they are moved around in a device. In the last few years methods have begun to appear which can do exactly this - on the relevant time, length and energy scales of electron motion in atomic scale designed devices.
To accomplish this we have combined a unique set of capabilities in making and operating highly controlled nanoscale electronic devices, imaging nanostructures surfaces to the atomic scale and squeezing laser pulses in time down to the attosecond timescale (light moves across an atom in roughly one attosecond – which is one quintillionth of a second).

We have now developed the methods to approach an extremely sharp metal tip to within one atomic layer distance of a running nanoscale electronic device. We can sweep the tip across the device, both imaging to the atomic scale and monitoring how the device function changes when we move tip around – at the nanoscale the probe is as large as the device itself.
The low dimensional semiconductors and metal (nano) structures studied have unique novel properties with potential applications in IT, life-science and renewable energy. We make the structures ourselves by a combination of self-assembly and lithographic patterning – structures can have parts which are perfected down to the single atom level.

In a second set of experiments we have shot high intensity attosecond and femtosecond laserpulses at our nanostructures and imaged the electrons released by this process. This experiment is terribly challenging as the necessary laser technology has only recently become available (and is still being invented) and it is then combined with advanced electron microscopy and design of nanostructures. Nonetheless we have managed to image a variety of nanostructures such as nanowire, nanoparticles, nanocubes and nanorice and several material systems using these ultra-fast laser beams. What we see is surprising new processes at these scales and how all the electrons act together coherently in surprising new ways.

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