Switching insulators to conductors at high rate

Scientists at the Wigner Research Centre for Physics of ELKH have reached an important milestone on the pathway toward ultrafast optoelectronic devices. Members of the Ultrafast Nanooptics Research group led by Péter Dombi, within an international collaboration involving attoworld-researchers around the Field-resolved Nano-spectroscopy group of Matthias Kling, made different insulating media conductive with a state-of-the-art compact laser source.

Researches at Wigner RCP have now made a huge step towards faster and more effective signal processing circuits. They exploited a recently discovered effect that allows to momentarily convert an insulating material (e.g. glass) into a conductor. This change of the state of matter lasts only for the time when the insulator is illuminated with an extremely short flash of laser light. But this time is long enough for the electrons to be transported by the action of the laser and to induce electric current in insulators. The team of scientists from the Ultrafast Nanooptics group led by Péter Dombi managed to trigger this effect in a special device with parameters adjusted to work with a simple laser oscillator. They succeeded to control the direction of the electric current at MHz repetition rates.

„It is fascinating to see in the lab, how an ultrashort laser pulse transforms insulators to a conductor within only a few femtoseconds. This effect has only been demonstrated with large, complex laser systems. Now, we managed to show this with a compact laser which is a very important step toward practical applications,” says Péter Dombi.

Origin publication

V. Hanus, V. Csajbók, Z. Pápa, J. Budai, Z. Márton, G. Kiss, P. Sándor, P. Paul, A. Szeghalmi, Z. Wang, B. Bergues, M. Kling, G. Molnár, J. Volk, P. Dombi

Light-field-driven current control in solids with pJ-level laser pulses at 80 MHz repetition rate


Sample under investigation, mounted in a sample holder, illuminated with laser and connected to acquisition electronics. (Source: Wigner Research Centre for Physics)

26th April 2021