Innsbruck / Hamburg, April 23, 2026 -- Physicists at ParityQC have demonstrated that universal quantum computation driven purely by measurements in the YZ-plane of the Bloch sphere is possible. The resulting measurement patterns embed naturally into the ParityQC Architecture — providing  a translation from ParityQC Architecture concepts to a measurement-based quantum computing (MBQC) paradigm.

Measurement-based quantum computing is a model of quantum computation, where the execution of a given algorithm is driven by single-qubit measurements performed in a prescribed order on a large entangled quantum state, rather than by gate sequences applied to sets of qubits. Each single-qubit measurement in MBQC can be visualized on the Bloch sphere. Collectively, these measurements are referred to as a measurement pattern. It has previously been shown that universal MBQC is possible when the measurements in the pattern are restricted to lie either entirely in the XY-plane of the Bloch sphere, or entirely in the XZ-plane.

In the new paper “YZ-plane measurement-based quantum computation: Universality and Parity Architecture implementation”, a team of physicists at ParityQC (Jaroslav Kysela, Katharina Ludwig, Nitica Sakharwade, Anette Messinger and Wolfgang Lechner) demonstrate that universal MBQC is also possible when all measurements are restricted to lie in the YZ-plane of the Bloch sphere. This work completes the line of research into the universality of patterns with measurements restricted to one of the principal planes of the Bloch sphere. Further to this, it is shown how the patterns can be embedded into graphs that feature only local interactions. This modification eliminates the need for long-range interactions, and is therefore amenable for implementation on existing hardware platforms. This work represents the introduction of ideas and concepts of the ParityQC Architecture and ParityQC Twine to the realm of the measurement-based quantum computing.

Completing the picture of single-plane universality

The paper presents a universal YZ-plane-only measurement pattern and establishes a precise connection between YZ-plane-only and XZ-plane-only computation, unifying two threads of research that had previously been treated separately. These results conclusively close the line of investigation into which principal planes of the Bloch sphere are sufficient for universal MBQC.

The ParityQC Architecture as a natural MBQC platform

The ParityQC Architecture encodes logical variables into parity qubits arranged so that all interactions are local. This structure, previously understood primarily in the context of quantum annealing and gate-based computing, now also emerges as a natural register-logic graph for YZ-plane MBQC. The bipartite structure of parity codes, in which data qubits and parity qubits form separate partitions, maps directly onto the graph-state requirements derived in the paper.

This alignment means that hardware built around the ParityQC Architecture can support universal measurement-based quantum computation with a highly restricted and experimentally convenient measurement set, thus reducing the demands on the physical layer while retaining full computational power.

Key points of the work:

• Systematic study of limitations of YZ-plane patterns: The measurement patterns with only YZ-plane measurements that comply with the uniform determinism described by the pattern’s flow are too restrictive to support universal computation.
• Universal YZ-plane patterns: A universal pattern of YZ-plane measurements can be designed and is demonstrated explicitly, when uniform determinism is abandoned in exchange for a more relaxed notion of determinism.
• Direct embedding into the ParityQC Architecture: YZ-plane patterns can be embedded into the ParityQC Architecture, where the graphs underlying the computation have only local interactions eliminating completely the hard-to-implement long-range interactions.
• Connection between YZ-plane and XZ-plane computation: A precise relationship between YZ-plane-only and XZ-plane-only MBQC patterns is established, closing the open research thread on single-principal-plane universality.