Extracting GHZ states from linear cluster states
Bibliographic record
Abstract
Quantum information processing architectures typically only allow for nearest-neighbor entanglement creation. In many cases, this prevents the direct generation of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>GHZ</a:mi></a:math> states, which are commonly used for many communication and computation tasks. Here, we show how to obtain <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>GHZ</b:mi></b:math> states between nodes in a network that are connected in a straight line, naturally allowing them to initially share linear cluster states. We prove a strict upper bound of <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mo>⌊</c:mo><c:mo>(</c:mo><c:mi>n</c:mi><c:mo>+</c:mo><c:mn>3</c:mn><c:mo>)</c:mo><c:mo>/</c:mo><c:mn>2</c:mn><c:mo>⌋</c:mo></c:mrow></c:math> on the size of the set of nodes sharing a <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mi>GHZ</d:mi></d:math> state that can be obtained from a linear cluster state of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mi>n</e:mi></e:math> qubits, using local Clifford unitaries, local Pauli measurements, and classical communication. Furthermore, we completely characterize all selections of nodes below this threshold that can share a <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mi>GHZ</f:mi></f:math> state obtained within this setting. Finally, we demonstrate these transformations on the IBMQ Montreal quantum device for linear cluster states of up to <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"><g:mrow><g:mi>n</g:mi><g:mo>=</g:mo><g:mn>19</g:mn></g:mrow></g:math> qubits. Published by the American Physical Society 2024
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".