On the Caltech campus, the term “quantum supremacy” has echoed through research labs and corporate boardrooms since a 2012 paper introduced it to the world. The man who gave the phrase its staying power is John Preskill, a theoretical physicist whose career at the university has spanned decades. Preskill, who earned his doctorate from Harvard University in 1980, coined the term to describe the threshold at which a quantum computer can perform a calculation that no classical computer can solve in a feasible amount of time.
Since then, the phrase has become both a rallying cry and a point of contention across the technology sector. Preskill directs the Institute for Quantum Information and Matter (IQIM), a research center he has led since its founding in 2006.
His own foundational contributions to the field include deep work on quantum error correction and fault-tolerant quantum computing, areas that have shaped the discipline’s trajectory from theoretical speculation toward practical engineering.
From Coining a Term to Defining an Era
Preskill’s intellectual path began with a Harvard Ph.D. in 1980, and he originally made contributions to particle physics and cosmology before shifting his focus toward quantum information in the late nineteen-nineties. His coinage of “quantum supremacy” in 2012 crystallized a shared aspiration across the research community: the moment when a quantum device solves a task beyond the reach of any conventional computer in practical time. The concept mattered because it provided a clear milestone for measuring progress.
By 2018, Preskill published a paper titled “Quantum Computing in the NISQ Era,” where NISQ stands for “noisy intermediate-scale quantum.” That work acknowledged that the quantum devices of the near future would be imperfect but still capable of specialized tasks. His honors reflect the weight of his contributions: he received the Dirac Medal in 2019 and is a member of the National Academy of Sciences.
Preskill’s career arc — from theoretical physics to the leadership of a dedicated institute at Caltech — mirrors the field’s own evolution from seminar-room speculation to laboratory milestones and corporate roadmaps.
The State of Play in Summer 2026
By the summer of 2026, the conversation around quantum computing has shifted. The fully error-corrected, general-purpose quantum computer that Preskill and his peers have described remains a goal for the future, not a present reality.
Inside the IQIM, research moves forward on multiple fronts: better qubits, more efficient error-correcting codes, and algorithms designed for the NISQ devices that exist today. Preskill, still the director, remains engaged in guiding this work. The question now is how quickly the field can move from supremacy on a single contrived problem to supremacy on something that matters — a calculation in materials science, a simulation of a new molecule, or a breakthrough in cryptography.
Preskill’s own work suggests the path is long, but it is no longer hypothetical. The devices are here.
The noise is real. And the race is on.
Broader Implications and What Comes Next
Quantum computing emerged from decades of theoretical work in physics and computer science, tracing back to ideas first proposed in the early nineteen-eighties. Early researchers explored how quantum mechanics — long confined to textbooks — could be harnessed to process information in ways classical machines cannot.
Preskill entered this field as a trained theoretical physicist with a Harvard doctorate, already known for contributions to particle physics and cosmology. His insights into error correction and fault tolerance became central to the discipline’s development. The stakes are both technical and economic: breakthroughs could reshape cryptography, materials science, and optimization problems that underpin industries from finance to pharmaceuticals.
Whether or not the next quantum machine crosses the supremacy line, the field’s trajectory reflects a broader shift from pure theory to engineering with real-world consequences. Preskill’s leadership at Caltech through the IQIM has helped anchor academic inquiry amid growing commercial and governmental interest, ensuring that the pursuit of quantum advantage remains grounded in rigorous science even as the race accelerates.
