After decades of patient quantum computer science groundwork, the notion of “quantum computing” has, in the past several years, seen a surge in new activity and interest—not only in the lab, but at commercial firms, and even among the public at large. Spurring that new interest has been successful lab demonstrations of systems and simulations involving multiple quantum bits (qubits) in trapped-ion systems, superconducting circuits, and other platforms.
But it’s still a long way from these demos to the kind of universal, fault-tolerant quantum machine that optimists have envisioned – one that can outperform the best classical computers on a wide range of problems. And some have questioned whether such machines are even possible.
In thinking about the feasibility of quantum computer science, a long view is essential. The extended history of classical computing before it started to take off during the 1970s with advances in integrated circuits; quantum technology could experience a similar “phase transition” in the future. Looking at the broader history of innovation, people tend to overestimate what can be done in three years, and underestimate what can be done in a decade. Sometimes, a technology infrastructure takes a long time to develop. But once it’s available, use cases quickly come about.