How is nanophotonics helping to push the boundaries of quantum technologies?

Photonics is a crucial enabling resource for quantum technology. Photons, with energies ranging from the GHz to the visible in the electromagnetic spectrum, are integral to almost all quantum technology platforms developed so far, from superconducting qubits to trapped Rydberg atoms. Due to their compatibility with electronic technology and its miniaturization potential, attention has focused lately on solid-state systems, where electron spins, vacancy centres or quantum dots play the role of qubits, whose interactions are assisted by photons. Importantly, photons themselves can also function as flying qubits, exploiting properties such as polarization or propagation path. Nanophotonics—centered on pushing the limits of spatial light manipulation and concentration, even beyond the subwavelength scale—has naturally emerged as a key resource in this context.

What is the most impactful breakthrough you have seen in quantum over your career?

That's a difficult question to answer. Letting myself be guided by the novelty of recent developments, I would highlight the progress made in recent years by various companies and academic institutions in scaling up quantum hardware and improving error control and correction in systems with an increasing number of qubits. The real challenges, both intellectual and technical, of quantum technologies do not lie within quantum mechanics itself, which this 2025 becomes a century old, but rather at its interface with the macroscopic world we humans inhabit. Achieving isolation and preserving properties such as quantum coherence and entanglement across a growing number of operations involving multiple elements while being able to initialize and read them under real-world conditions, with temperature, noise, and many sources of decoherence, remains the greatest quest. That is why I consider these recent steps along this line to be the most significant.

How do you see quantum evolving in the next decade, and what breakthroughs might we expect?

I will deliberately avoid making predictions about the short-term future of quantum technologies, as they are likely to enter (they have already) an area beyond my expertise: the development and commercialization of applications based on them. However, I do believe that in the coming years, the way quantum mechanics is introduced in undergraduate physics programs (and similar fields) will change significantly. This is something I have recently discussed with my colleagues, and steps in this direction have already been taken in some universities. For many generations, students, after acquiring a deep understanding of various areas of classical physics (such as mechanics and electromagnetism), would approach quantum mechanics through atomic physics—the field where quantum coherence, which gives rise to phenomena so distinct from the classical world, manifests most clearly and distinctly. I believe this approach has been driven by historical reasons. I am convinced, however, that this will change in the coming years, with quantum mechanics being introduced (at least partially) from the perspective of open quantum systems, establishing the connection between classical (macroscopic) and quantum (microscopic) physics, thus avoiding the intellectually challenging leap students have had to make for so long. This shift will also offer students a practical perspective on the field, which will be crucial for training professionals with the optimal background for quantum engineering.