A team from the University of Chicago, Purdue University, Boston University, and the startup AppliedTQC published a superconducting circuit design on July 21, 2026, that reproduces a Z3 combinatorial gauge symmetry, a property theorists consider essential for building topologically protected qubits. Read that sentence carefully. It's a validated building block, not a topological qubit, and the researchers themselves say so.
What they built
The device is a 3x3 crossbar array of Josephson junctions, nine junctions total, formed by three horizontal and three vertical superconducting wires crossing on a silicon substrate. The team calls it a "waffle grid," and it deliberately breaks from the planar circuit layouts IBM and Google use in their superconducting processors. Under precisely tuned magnetic fields, the circuit exhibited six equivalent low-energy states, matching what theory predicted for this symmetry. The team validated the measurements using neural-network variational Monte Carlo simulations, and the device is currently operating in the semiclassical regime, meaning quantum tunneling between those states is present but weak.
Why gauge symmetry matters for topological qubits
Topological qubits store information in the global, non-local properties of a system rather than in the state of any single physical object, which is the theoretical appeal: information encoded this way is supposed to be inherently resistant to the local noise that plagues conventional qubits. Microsoft's long-running, still-contested pursuit of Majorana-based topological qubits is the best-known attempt at this approach. This result is a different route to the same destination: rather than searching for exotic quasiparticles in a material, the UChicago-led team engineered the required symmetry directly into a superconducting circuit built from ordinary Josephson junctions.
What the researchers themselves say is next
The team frames this explicitly as validation of a foundational building block, not a functioning topological qubit. Their own stated next step is to push the device deeper into the quantum regime, where tunneling dominates over classical thermal noise, and then tile many of these waffle units into a honeycomb lattice to produce genuinely topologically ordered states. Both of those are separate, harder engineering problems that haven't been demonstrated yet.
How to read this next to other qubit modality news
This site tracks a lot of "new qubit modality" announcements: SAXON Q's room-temperature diamond qubits, HRL's self-correcting silicon spin processor, and Warwick's phononic interconnect concept all landed in the same category: a real, checkable physics result that validates one piece of a much larger, unfinished architecture. None of these results, this one included, is a working error-corrected qubit available to buy or rent. Our modality comparison covers where each approach stands relative to the superconducting and trapped-ion platforms that already have commercial systems in the field.
What to watch next
The two milestones the researchers named themselves are the ones to track: operation deep in the quantum regime, and a working honeycomb lattice of multiple waffle units showing topological order rather than a single cell's symmetry. Until either lands, this is a genuine and welcome physics result, and nothing more than that yet.