Welcome to issue #20 of This Week in Quantum — a roundup of the most important developments in quantum computing from July 20-26, 2026.
The week’s biggest story wasn’t a new quantum computer — it was a laptop. Researchers at the Flatiron Institute showed that classical tensor-network methods can match quantum hardware on a problem once held up as evidence of “beyond-classical” performance, reopening a debate about where the real quantum advantage lies. Elsewhere, post-quantum cryptography kept moving from policy documents into working products, and the industry’s biggest players opened up new ways for outside researchers to get hands-on with their machines.
Industry News
Quantinuum launches a global challenge for quantum computing solutions
On July 25, Quantinuum announced the SG Grand Challenge 2026, a three-month program giving global teams access to its quantum computing resources and mentorship to tackle problems in chemistry, optimization, AI, error correction, materials science, and open innovation. The program is organized with support from Singapore’s National Quantum Office and Aqora, underscoring Singapore’s growing investment in the field.
Infleqtion wins three DOE projects for quantum AI and sensing
Also on July 25, neutral-atom quantum company Infleqtion announced it had won three separate U.S. Department of Energy projects spanning quantum AI and quantum sensing applications, adding to a string of government contracts the company has picked up through 2026.
Research Highlights
A laptop matches a quantum computer on a problem once thought to need one
On July 20, physicists at the Simons Foundation’s Flatiron Institute, working with Boston University, reported using tensor networks to compress the wave function of hundreds of entangled qubits — lead author Joseph Tindall described the technique as “a zip file for the wave function” — and ran the resulting calculation on an ordinary laptop. The results matched both theoretical predictions and prior quantum-hardware simulations, directly challenging an earlier “beyond-classical” claim. The tensor-network method could open new avenues for studying quantum dynamics and materials using classical machines, at least for this class of problem.
Security Watch
Terra Quantum and Apex.AI demonstrate post-quantum cryptography for robotics
On July 23, Terra Quantum and Apex.AI announced a working implementation of NIST-standardized post-quantum cryptography securing communication between an Apex.AI-based robotic software environment and a cloud control system. The demonstration is aimed at long-lived, cloud-connected systems — robotics, autonomous vehicles, defense platforms — that need quantum-resistant security without a fundamental rewrite of existing software architectures.
The Bigger Picture
This week’s tensor-network result is a useful check on the industry’s own hype: not every hard quantum simulation is proof that a quantum computer was necessary, and distinguishing genuine quantum advantage from classical catch-up is going to stay an active, contested question for years yet. At the same time, the steady drumbeat of post-quantum cryptography pilots — this week in robotics, in prior weeks in finance and government — shows the defensive side of the field moving ahead regardless of exactly when cryptographically relevant quantum computers arrive.
Upcoming Events
- July 27 — Workshop on Broadly Accessible Quantum Computing at PEARC'26, Minneapolis
- July 27 — D-Wave Nasdaq listing debut
- September 9-11 — Quantum Expo Korea 2026, Seoul
- September 13-18 — IEEE Quantum Week, Toronto