PASADENA, July 13 — On the third floor of the California Institute of Technology, inside the Institute for Quantum Information and Matter, John Preskill is watching the future unfold in real time. The theoretical physicist, who has spent decades mapping the strange terrain of quantum mechanics, now finds himself at the center of a field that is racing toward its next great milestone. Preskill, an American theoretical physicist and professor at Caltech, first gave the quantum computing world its most famous target.
In a 2012 blog post, he coined the term “quantum supremacy.” He defined it as the moment a quantum computer can solve a problem that no classical computer can solve in a reasonable time. That concept became a keystone of the entire field.
The Supremacy Milestone
By 2019, Google had achieved that milestone. Preskill’s term had moved from theoretical physics into the engineering headlines. The achievement validated the roadmap he had helped lay out.
But Preskill did not stop at defining the finish line. He also gave the field its name for the current moment.
In his 2018 paper “Quantum Computing in the NISQ Era,” he introduced the term “NISQ” — Noisy Intermediate-Scale Quantum. This describes the era researchers are living through right now: quantum computers with imperfect qubits, not yet fully error-corrected.
On the Ground at Caltech
On the ground at Caltech, Preskill leads the Institute for Quantum Information and Matter, known as IQIM. The institute is a hub for researchers pushing at the boundaries of quantum information theory. Preskill’s own contributions have ranged from studies of quantum error correction to the black hole information paradox — the long-standing puzzle about what happens to information when it falls into a black hole.
The scene inside IQIM is one of intense, quiet focus. Researchers here are working on the next generation of quantum processors, trying to reduce noise in qubits and build systems that can sustain longer calculations.
By nightfall, the lights in the labs are often still on.
What Comes Next
The NISQ era, as Preskill defined it, is not a permanent state. It is a waystation. The goal is fault-tolerant quantum computing — machines that can correct their own errors and run algorithms of arbitrary length.
Preskill’s work on quantum error correction is a direct contribution to that long-term aim. For now, the field is in a strange middle ground.
The machines exist. They work. But they are noisy, fragile, and limited.
Preskill’s 2018 paper gave researchers a framework for understanding exactly where they stand — and what they need to build next. The term “quantum supremacy” itself has evolved.
Some researchers now prefer “quantum advantage,” arguing that the original phrase carried an uncomfortable edge. But the concept remains the same: a clear, measurable point where quantum computing proves its worth. Preskill’s influence runs through every part of this story.
He named the goal. He named the current era. And he continues to lead the research that will carry the field into whatever comes after NISQ.
What to watch next: the race toward error-corrected quantum processors. The noisy intermediate-scale machines of today are laying the groundwork.
Preskill and his colleagues at Caltech’s IQIM are among those pushing hardest toward the next threshold — a fully fault-tolerant quantum computer that could change everything from cryptography to materials science. The field he helped define is still moving fast. And John Preskill is still on the ground, watching it happen.
