HexaCore: Modular Quantum Processor Architecture

The Research Question

Large superconducting quantum processors face a difficult tradeoff: additional connectivity can reduce routing overhead, but every physical coupling also carries fabrication, calibration, control and crosstalk cost.

HexaCore was created to test that question rather than assume the answer. The architecture was evaluated first with static graph metrics and then subjected to progressively stronger tests including routed compilation, workload analysis, intermodule-traffic reconstruction, authenticated control comparison, error-cost modeling and duration-aware scheduling.

Architecture Under Evaluation

The reference HexaCore family contains seven 15-qubit modules: one central module and six peripheral modules. Local modules use regular nearest-neighbor connectivity while a fixed set of intermodule links connects the system.

The intermodule-link budget is fixed at design time and can be distributed among different module-to-module connection classes. The study explored the resulting design space while preserving qubit count, coupling budget and degree constraints.

What Stronger Testing Found

Early static analysis produced an encouraging result. Stronger routed compilation subsequently reversed that conclusion.

This falsified the simple hypothesis that the modular topology was intrinsically more routing-efficient than the denser Willow reference. The adverse result was preserved and became the basis for the next phase of the investigation.

What Survived the Falsification

The investigation identified a narrower but reproducible architectural effect: the placement strategy strongly determines how often routed two-qubit operations must cross module boundaries.

This matters because intermodule operations are likely to be among the most expensive operations in a physically modular processor. The surviving HexaCore claim is therefore not that modular topology is universally faster. It is that link allocation and workload placement jointly control the traffic placed on the costly part of a modular system.

From Architecture Claim to Hardware Requirements

After the routed penalty was established, verified circuit reconstructions were used to ask a different question: what physical device characteristics would be required for the modular architecture to recover that disadvantage?

Evidence Status

Each conclusion is kept at the level supported by the current evidence.

Where Device Expertise Becomes Essential

The computational work has reduced the remaining questions to device, interconnect, packaging and control engineering. These are no longer questions that graph simulation alone can answer.

Research Approach

HexaCore is being developed under an evidence-first process in which unfavorable results are retained rather than optimized away. The study progressed through static screening, routed compilation, workload-validity analysis, telemetry reconstruction, authenticated control verification, error sensitivity and exact duration-aware scheduling.

One of the principal findings of the program is methodological: attractive graph metrics are insufficient evidence for a processor architecture. Placement policy, routed compilation, workload structure, physical link cost and scheduling constraints must be evaluated together.

Intellectual Property & Technical Collaboration

Elements of the HexaCore architecture family and associated evaluation methods are the subject of pending intellectual-property filings. This page presents selected research findings and does not disclose all architecture, implementation, optimization or validation details.

Quantum Clarity welcomes confidential technical discussions with superconducting-device, quantum packaging, interconnect, compiler and systems researchers interested in independently assessing the remaining feasibility questions.