The future landscape of computing is poised for a revolutionary transformation as scientists unveil a groundbreaking approach to ultrafast logical operations driven by light itself. In a landmark study recently published in Nature Photonics, researchers from the Department of Physics at Politecnico di Milano, in collaboration with the Istituto di Fotonica e Nanotecnologie (IFN) of the National Research Council (CNR) and other international institutions, have demonstrated the potential of femtosecond-scale light pulses to control quantum states of matter and thereby execute computational tasks at unprecedented speeds.
Traditional electronic devices rely fundamentally on the movement of electrons within semiconductor transistors, a process inherently limited by the maximum frequency that charge carriers can sustain. Overcoming these limits has long been a challenge for physicists and engineers seeking faster and more efficient computing architectures. This novel research sidesteps these constraints by harnessing oscillating light waves to manipulate electrons within a nanometric material, marking a paradigm shift from charge-based electronics to photonics-driven computation.
The team, led by Professor Giulio Cerullo at Politecnico di Milano, alongside key collaborators including Professors Stefano Dal Conte, Margherita Maiuri, and researchers Francesco Gucci and Mattia Russo, employed ultrashort laser pulses lasting just a few femtoseconds—millionths of a billionth of a second—to achieve coherent control over electron quantum states. This ultrafast manipulation occurs at rates exceeding 10 terahertz, which is more than 100 times faster than the frequencies attainable in state-of-the-art electronic circuits, heralding a quantum leap in operational speeds for information processing devices.
Central to this revolutionary technique is the use of tungsten disulfide (WS₂), a two-dimensional semiconductor that is only three atomic layers thick. Due to its unique quantum mechanical properties, WS₂ features electrons inhabiting two discrete energy valleys that represent distinct quantum states. These “valley” states form the basis of a new form of information encoding, often referred to as valleytronics, which offers an alternative to classic binary computing bits. By selectively exciting these valleys with precision-tailored light pulses, researchers can encode, manipulate, and read quantum information with extraordinary speed and fidelity.
The experimental setup involves choreographing a sequence of light pulses to perform fundamental logical operations analogous to those used in electronic circuits. The researchers succeeded in turning quantum information on and off, as well as coherently expanding it, thus effectively demonstrating ultrafast computational functions. Remarkably, these experiments were conducted at room temperature, using laser pulses that are readily generated with current laboratory technology, underscoring the method’s promise for practical and scalable applications.
Another salient aspect of the study is the assessment of quantum coherence lifetimes, a critical factor determining how long quantum information can be preserved in the material without degradation. Stability of valley states is essential for reliable computing operations, and the ability to measure and manipulate these parameters opens pathways for future optimization. Understanding coherence dynamics will underpin the design of devices that fully exploit the ultrafast capabilities demonstrated.
Franco Camargo from IFN-CNR emphasizes the broader implications and future challenges entailed by this proof of concept. While the results mark a pivotal advance, they also reveal an array of scientific and engineering hurdles to surmount before ultrafast valleytronic devices can compete with or complement conventional semiconductor technology. These challenges include scaling up the complexity of laser pulse sequences and integrating a larger number of quantum bits into coherent architectures.
The study represents a compelling fusion of quantum optics and condensed matter physics, highlighting the interplay between light-matter interactions at the nanoscale to achieve functionality previously deemed impossible. By pushing computational speeds into the terahertz regime, this work places photonics at the forefront of next-generation computing hardware innovation—one that could shatter existing speed ceilings and lead to drastically enhanced data processing capabilities.
Moreover, the approach holds potential significance beyond classical computation, suggesting new routes toward quantum computing platforms that leverage coherent control over valley degrees of freedom. The principles demonstrated in this research may inspire novel quantum information processing devices that harness ultrafast light-driven control mechanisms, positioning valleytronics as a promising contender within the emerging quantum technology landscape.
As researchers continue to refine the techniques and explore material platforms compatible with ultrafast valley manipulation, the envisioned outcome is a new class of optoelectronic devices that vastly outperform today’s electronics both in speed and energy efficiency. The fusion of lightwave electronics and quantum state control underscores a fundamental shift in how information technology might evolve over the coming decades.
In summary, this trailblazing study lays the groundwork for a future where computational operations are dictated by the speed of light oscillations, rather than the drift of electrical charges. By combining advanced photonics, material science, and quantum physics, the team at Politecnico di Milano and their collaborators have opened a new frontier in information processing that could redefine the capabilities and architecture of computers well into the 21st century and beyond.
Subject of Research: Not applicable
Article Title: Encoding and manipulating ultrafast coherent valleytronic information with lightwaves
News Publication Date: 9-Jan-2026
Web References: http://dx.doi.org/10.1038/s41566-025-01823-w
References: Study published in Nature Photonics, DOI: 10.1038/s41566-025-01823-w
Image Credits: Politecnico di Milano
Keywords: Photonics, Applied optics, Laser systems, Lasers, Quantum optics, Photoelectrons, Electrons, Electronic devices, Optoelectronics, Electronics, Quantum computing, Light matter interactions, Electronic circuits
