Hungarian Physicists Generate Ultrafast Currents with Light

Pushing the Frontiers of Ultrafast Electronics

A groundbreaking discovery from Hungarian researchers could reshape the future of computing technology. Scientists at the HUN-REN Wigner Research Centre for Physics, in collaboration with the ELI Laser Research Institute, have demonstrated how light’s electric field can drive electrical currents through metals at unprecedented speeds. Their findings, published in Science Advances, reveal that such currents can oscillate in sync with electromagnetic fields vibrating in mere femtoseconds — that’s a quadrillionth of a second.

Today’s computers rely on minuscule electrical switches called transistors, toggling on and off by applying tiny voltages. These voltages create electric fields that push electrons through the device, altering its state. Yet, even these cutting-edge processes take a few nanoseconds — a relatively sluggish pace by modern standards. The limitation has long capped the speed of logical operations in conventional microelectronics.

The Hungarian team explored a radically faster alternative: using the electric field of light itself to move electrons and control optoelectronic devices. Instead of applying voltage across wires, they harnessed ultrashort laser pulses — lasting only a handful of femtoseconds — to directly excite electrons within a material. This method, known as light-controlled switching, holds the potential to be up to 100,000 times faster than current electronics, offering a path toward next-generation computing built around light-driven logic operations.

Custom-Built Materials for Precision Light Control

Central to this breakthrough was a unique material crafted from alternating nanometer-thin layers of iridium and sapphire. Created through an advanced atomic layer deposition technique by a German research group, this heterostructure was specifically designed for the Budapest laser lab’s experiments.

Beatrix Fehér, a PhD student involved in the project, emphasized the importance of this custom material. “We only tested structures a few atomic layers thick, and the properties of these tailored materials were essential for observing the ultrafast currents,” she explained. Co-author Václav Hanus noted that while laser-induced currents had been studied in glasses and semiconductors, applying the same principles to metals was uncharted territory.

The researchers essentially asked whether it was possible to generate current inside a metal without conventional electrical contacts, using nothing but light. The answer, it turns out, is a resounding yes — under precisely controlled laboratory conditions using sophisticated, high-powered laser systems.

From Laboratory Curiosity to Future Technology

The implications of this work extend far beyond academic curiosity. Dombi Péter, head of the Budapest-based research group, described the effort as an “exciting exploratory journey” into the ultrafast interactions between laser light and nanomaterials. “Within a few years, this could evolve into actual technology, which is the most thrilling prospect of our research,” he said.

As a tangible outcome of their work, the Hungarian team has already developed a compact optical device capable of characterizing laser beam properties with unprecedented ease and accuracy. This instrument alone promises immediate practical benefits for optical labs and laser-based industries.

A Glimpse Into a Light-Powered Computing Era

While this discovery marks a significant step, it’s part of a broader international effort to overcome the bottlenecks of traditional electronics. Researchers worldwide are racing to develop faster, energy-efficient computing systems by integrating photonics — the science of light — into data processing hardware. Ultrafast light-controlled switches could one day enable computers that process information not in nanoseconds but femtoseconds, transforming fields from AI to high-frequency trading and scientific simulations.

Interestingly, just last year a team from ETH Zurich demonstrated a similar light-based current generation in two-dimensional semiconductors, but the Budapest experiment is one of the first to achieve this in metallic systems. This places the Hungarian team’s work at the cutting edge of the emerging field of lightwave electronics — a domain that promises to redefine the very foundations of digital technology.