August 6, 2026 -- Our new research paper introduces the framework for a superconducting quantum computing architecture that expands on globally controlled coupling to eliminate physical overhead and enable error correction.

Planckian’s core thesis is that the most efficient path to scaling superconducting quantum computers is the processor that makes the most efficient use of multiplexed control lines to reduce the resource overhead that comes with qubit count. We believe global control — broadcasting microwave signals across many qubits at once — is the ultimate form of that leverage, and the only one that holds as conventional multiplexing techniques reach their limits under the demands of error correction.

In our early work we demonstrated, both theoretically and experimentally, that superconducting architectures based on globally driven schemes can be engineered and built by leveraging always-on ZZ interactions. These architectures overcome the difficulty of addressing individual qubits when many share the same signal through auxiliary qubits that act as markers and hold no computational information. This carries a cost: an overhead of physical qubits per chip, with the associated yield and error-rate penalties. It has a sharper consequence too. Because auxiliary qubits are not protected by the code that corrects the computational qubits, error correction requires a separate and costly procedure running alongside the first, and cannot be applied uniformly across the device.

Our new research presents the framework for a chip architecture, still based on global control, that removes the need for auxiliary qubits entirely. In its first topology, qubits are arranged in a homogeneous loop with two global coupling patterns that transport information around it, plus a single locally addressable site. Any qubit can be routed to that site, and any pair brought there together, which is sufficient for universal computation. The mechanism is a globally controlled tunable coupler inducing a native iSWAP interaction, compiled into the SWAP operations that move information around the loop.

Because every physical qubit is now a computational qubit, a single error-correcting code protects the entire register. We identify a family of cyclic stabilizer codes whose syndrome extraction is built natively from the loop’s global operations, and whose physical qubit count grows linearly rather than quadratically with code distance. Our next focus is designing a new family of QEC codes that exploit the advantages of globally driven architectures to build the most efficient utility-scale quantum computer.