A team of laser physicists led by Prof. Eleftherios Goulielmakis, head of the Extreme Photonics working group at the Institute of Physics at the University of Rostock, has now generated and measured the shortest electron pulse to date using ultra-short laser pulses. In the process, the electrons were extracted from a tiny tungsten nanotip with the help of the light. This took only 53 attoseconds.
To determine the duration of the pulses, the team developed a new camera that takes snapshots of the electrons during the ultrashort period in which they are transported out of the nanotip into the vacuum by the laser. "The trick was to use a second, very weak flash of light," says Dr Hee-Yong Kim, lead author of the study. "This second laser flash modifies the energy of the electron pulse produced, so we can find out what it looked like over time," he adds. "It's a bit like the game of 'What's in the box?" where you try to identify an object without looking, just by feeling its shape with your hands," he continues.
With the study, the results of which have now been published in the scientific journal "Nature", the researchers set a new speed record for controlling electrical currents in solid materials.
Picture: Eleftherios Goulielmakis

Original publication:
H.Y. Kim, M. Garg, S. Mandal, L. Seiffert, T. Fennel & E. Goulielmakis Attosecond Field Emission
Attosecond field emission
Nature 613, 662 (2023)