Emmanuel Zambrini Cruzeiro, a quantum information specialist at Instituto Superior Técnico, cuts through the hype around Google's Willow chip with a straightforward distinction: quantum computing isn't about speed per se. It's about a fundamentally different way of processing information using the strange rules of quantum mechanics.
A classical computer reduces everything to transistors—billions of them jammed into smaller spaces, each representing a 0 or 1. We're hitting a wall. Transistors are approaching atomic scale; shrinking them further violates the laws of physics. This is the dying gasp of Moore's Law, and it's why companies like IBM, Google, and Microsoft are betting billions on quantum alternatives. But a quantum computer doesn't solve the problem by doing more of the same thing faster. It exploits superposition—the ability of a quantum bit (qubit) to exist in multiple states simultaneously until measured—and interference, where certain calculation pathways amplify while others cancel out. This is radically different from classical parallelization.
The catch: quantum computers are probabilistic machines. You run them many times, measure the results, and extract probabilities. For simple problems—the kind your laptop handles daily—this overhead makes quantum useless. Google's recent claim that Willow solved a mathematical puzzle septillion times faster than a classical computer is technically true but meaningless in practical terms. Nobody actually needs to solve that particular puzzle. The real applications lie elsewhere: simulating molecular structures for drug discovery, modeling materials science, and understanding complex physical systems where classical computers simply drown in the computational space.
The security threat, however, is real and urgent. Peter Shor's algorithm, discovered in the 1990s, shows that a sufficiently large quantum computer could factor the integers underlying RSA encryption—the protocol protecting most internet traffic—in polynomial time instead of exponential time. This isn't imminent. Breaking current RSA keys would require thousands of logical qubits; today's machines have dozens of noisy ones. But governments and intelligence agencies are already preparing. The "store now, decrypt later" scenario—capturing encrypted data today and decrypting it with future quantum computers—is why cryptographic migration to quantum-resistant algorithms has become a priority for NATO, the EU, and national security establishments. China and the US are racing to build quantum internet infrastructure; Europe has launched the Quantum Internet Alliance. This isn't speculation; it's active policy.
The state of the art in early 2025 shows IBM promising networked quantum processors communicating via quantum channels—a distributed architecture that could modularly scale to thousands of qubits. Researchers already have access to cloud-based systems from IBM and others. The critical milestone Willow achieved wasn't raw qubit count but implementing error correction during computation, proving that scaling doesn't necessarily mean noise compounds forever. This changes the trajectory from "quantum computing is impossible" to "quantum computing requires engineering."
For most people, quantum laptops are fantasy. The cryogenic infrastructure alone—cooling superconducting qubits to near absolute zero—requires room-sized equipment. Photonic quantum computers might eventually work at ambient temperature, but they're years behind. The near-term winners will be governments, militaries, and pharmaceutical companies solving specific problems that classical computers cannot. Everyone else will benefit indirectly, through better drugs and materials, once the technology matures. The hype should settle. Quantum computing is important and real. It's just not coming to your pocket.