Science Daily April 26, 2023
Researchers in Germany have shown that by superimposing two laser fields of different strengths and frequency, the electron emission of metals can be measured and controlled precisely to a few attoseconds. So far, scientists have only been able to determine laser-induced electron dynamics precisely in gases with an accuracy of a few attoseconds. Quantum dynamics and emission time windows have not yet been measured on solids. Instead of just a strong laser pulse, which emits the electrons a pointy tungsten tip, they also used a second weaker laser with twice the frequency. The electrons then tunnel through the metal interface into the vacuum. By deliberately superimposing the two light waves, they could control the shape and strength of the laser field — and thus the emission of the electrons. They were able to determine the duration of the electron flow to 30 attoseconds. This ultra-precise limitation of the emission time window could advance basic and application-related research, gain deeper insights into the tunnel process and the subsequent movement of the electron in the laser field. This enables new quantum mechanical insights into both the emission from the solid state body and the light fields used. According to the researchers in the foreseeable future, it will be possible to integrate the components of test setup into a microchip, and complex circuits with bandwidths up to the petahertz range are then conceivable that would be almost a million times faster than current electronics… read more.
TECHNICAL ARTICLE
Schematic representation of the experiment. Credit: Nature volume 616, pages702–706 (2023)