PsiQuantum, a UK-founded startup, is pursuing an unconventional path to quantum computing by using particles of light instead of superconducting circuits or trapped ions. The company plans to house its quantum computer in roughly 100 stainless-steel cabinets cooled to near absolute zero, where thousands of photons will travel through optical switches and beam splitters to perform calculations that classical computers might take millions of years to solve.

Unlike IBM and Google, which are betting on superconducting qubits, or Intel, which uses electrons, PsiQuantum's photonic approach represents a fundamentally different engineering choice in the crowded quantum computing race. The company has attracted significant momentum: it raised $1 billion in funding last year, broke ground on a facility in Chicago in partnership with local governments, and is one of just two companies, alongside Microsoft, to reach the third stage of an intensive government evaluation program designed to identify which quantum companies might succeed.

Why Would a Photon-Based Quantum Computer Matter?

The promise of quantum computing hinges on a fundamental difference from classical computers. While traditional bits are either 1 or 0, quantum bits, or qubits, can exist in multiple states simultaneously, a property called superposition. When enough qubits work together, they could theoretically solve problems that would be intractable for even the most powerful conventional machines.

The real-world applications are staggering. Consider how scientists currently struggle to predict which lithium-ion batteries will catch fire or how quickly critical aircraft components will corrode. These failures stem from quantum mechanical processes at the atomic and molecular level, yet scientists lack the computational power to model them precisely. Instead, they rely on approximations, imperfect simulations, or animal testing. A quantum computer powerful enough to simulate quantum systems directly could transform drug design, materials science, and battery safety.

PsiQuantum's most ambitious claim involves pharmaceutical research. The company aims to predict how cytochrome P450 enzymes break down drugs in the body, a calculation that currently takes over 10 years using conventional methods. According to the company's vice president of quantum applications, they aim to reduce this to just four minutes.

What Makes PsiQuantum's Approach Different From Competitors?

PsiQuantum was founded in 2016 by four physicists from UK universities: Terry Rudolph, Mark Thompson, Pete Shadbolt, and Jeremy O'Brien. Each took on a distinct role in the company's mission. Rudolph focused on the theoretical foundations, Thompson on engineering, Shadbolt on scaling the technology, and O'Brien on articulating the vision and securing investment. Victor Peng, a veteran of the semiconductor industry, took over as CEO in February 2026.

The company's most distinctive advantage is its partnership with existing semiconductor manufacturers. Rather than building quantum computers from scratch, PsiQuantum is working with major chip manufacturers to produce its systems using established semiconductor fabrication plants. This approach could accelerate production and reduce costs compared to competitors building entirely custom hardware.

PsiQuantum has also announced plans for a second facility in Australia, which it promises will be hardware-ready by 2027. These concrete timelines and infrastructure investments set the company apart in a field often characterized by vague promises and theoretical breakthroughs.

How Do Photons Work as Qubits?

• Delicate Quantum States: Quantum systems are inherently fragile; observing a particle causes it to collapse from a superposition of multiple states into a single state, which introduces errors if it happens during computation rather than at the end.
• Precision Measurement: Each photon must be precisely tracked as it travels through optical switches and beam splitters, because measuring where it ends up provides the answer to the quantum calculation.
• Error Correction Challenge: Too many measurement errors during computation cause the quantum computer to fail and produce useless results, making error correction a critical engineering problem.
• Material Innovation: PsiQuantum manufactures its own barium titanate, a material with ideal properties for routing light particles through the quantum processor.

When Will We Know If PsiQuantum's Vision Works?

The company is approaching what industry observers call its "prove-it moment." Years of closed-door work and hundreds of millions in investment will either culminate in a useful quantum computer or fall short. Evaluating quantum computing progress is harder than assessing a pharmaceutical company through clinical trials because advances are incremental, opaque, and difficult to verify from the outside.

However, the timeline is becoming concrete. PsiQuantum's Australian facility is expected to be hardware-ready in 2027, and observers could begin to see meaningful results as soon as next year, according to reporting on the company's roadmap.

"Whenever we have more power to calculate and simulate and understand things, we build incredible machines that come from it," said Terry Rudolph, PsiQuantum co-founder and chief scientific officer.

Terry Rudolph, Co-founder and Chief Scientific Officer, PsiQuantum

Rudolph drew a historical parallel to explain why quantum computing matters. Just as the Industrial Revolution coincided with humanity's ability to calculate and simulate Newtonian mechanics, thermodynamics, and classical electromagnetism, he argues that quantum computers will unlock a new era of innovation by allowing scientists to simulate quantum systems directly.

The quantum computing race remains wide open. No single approach has yet proven superior, and the field includes diverse bets on superconducting qubits, trapped ions, electrons, and now photons. PsiQuantum's photonic strategy, combined with its partnerships, funding, and government backing, positions it as one of the most credible contenders. But the real test will come when the company must demonstrate that its theoretical advantages translate into practical, commercially useful quantum computing power.