A University of Chicago-led team experimentally built a 3x3 Josephson-junction “waffle” circuit that reproduces the Z₃ gauge symmetry long proposed as a building block for topological quantum computers.
At a specific magnetic field, the device settled into six equivalent low-energy states and produced microwave spectra that matched theoretical predictions and neural-network Monte Carlo simulations.
The non-planar crossbar design departs from the flat nearest-neighbor layouts used in superconducting systems from IBM and Google, enabling interactions conventional planar chips cannot realize.
The result does not create a usable topological qubit yet; the team tested a single device in the semiclassical regime, while a practical machine would require many such waffles tiled into a larger honeycomb lattice.
Beyond quantum computing, the architecture could serve as a platform for simulating lattice gauge theories, frustrated magnets and other exotic quantum phases; the study is currently an arXiv preprint.
Does this circuit's success signal a new, more viable path for topological quantum computing after years of slow progress?
How does a 'waffle' shape physically protect fragile quantum data, a feat that has stumped engineers for decades?
University of Chicago’s 2024 Advances: Modular Quantum Processors and Tunable Topological Superconductors for Scalable, Fault-Tolerant Computing
Overview
In December 2024, the Pritzker School of Molecular Engineering at the University of Chicago announced major breakthroughs in topological quantum computing, driven by the Cleland and Yang labs. Their research combines advances in foundational materials, like tunable topological superconductor thin films developed by Shuolong Yang’s team, with innovative architectural designs for robust quantum systems. By focusing on both the creation and characterization of key materials and the development of scalable processor architectures, these efforts mark a significant step toward building more stable and powerful quantum computers.