UNESCO launched the International Year of Quantum Science and Technology 2025: “100 Years of Quantum is Just the Beginning”. In fact, we are at the beginning of a secondquantum revolution. While the first gave us the foundations of quantum mechanics and enabled technologies like semiconductors, lasers, and magnetic resonance imaging, thesecond goes further: it allows us to directly control quantum systems — the so-called qubits — to process, communicate, and measure information in entirely new ways.
Qubits are units of information that work differently from traditional bits. While a bit can represent either 0 or 1, a qubit can represent both at the same time. Manipulating themopens up possibilities that were previously unthinkable. Quantum computers based on qubits already exist, developed by companies like IBM, Google, and various start-ups. Right now, these systems are still small-scale and have high error rates. However, if today’s technological challenges are overcome, quantum computers may one day solve extremely complex problems that conventional computers can’t handle. It’s important to note that quantum computers won’t replace current ones — they’ll complement them.
In communications, quantum key distribution for encryption enables ultra-secure connections, as the laws of quantum mechanics can be used to detect any intrusion attempt. Quantum communication networks are currently being developed worldwide, both through terrestrial systems (including in Portugal) and via satellite.
Another growing area is quantum sensing. Compact devices are being developed that can make extremely precise measurements of time, gravity, and magnetic fields. Promising prototypes already exist, with potential applications in healthcare, navigation, and geolocation.
The second quantum revolution is still in its early stages, but it promises to profoundly transform science, technology, and our daily lives. Europe — including Portugal — is anactive part of this global effort, involving education, scientific research, and partnerships with industry. We’re witnessing extraordinary developments at a surprising pace. Just like the internet in the 1990s, we are approaching a turning point.
Helena Vieira Alberto
Associate Professor, Department
of Physics, University of Coimbra
