Back to News
quantum-computing

Pauli Measurements Are Near-Optimal for Pure State Tomography

arXiv Quantum Physics
Loading...
3 min read
0 likes
⚡ Quantum Brief
Researchers from Caltech and MIT developed a near-optimal algorithm for pure state tomography using single-qubit Pauli measurements, reducing the required quantum copies from O(3ⁿ) to O(2ⁿ/ε) for an n-qubit state. The algorithm achieves fidelity 1−ε with high probability while using only nonadaptive Pauli measurements, simplifying experimental implementation compared to previous adaptive methods. Runtime scales polynomially with system size (poly(2ⁿ,1/ε)), making it computationally efficient for near-term quantum devices despite exponential sample complexity. This work improves the best-known copy complexity bound by a factor of 3ⁿ/2ⁿ, representing a fundamental advance in quantum state reconstruction efficiency. The findings suggest Pauli measurements may be theoretically optimal for pure state tomography, with implications for quantum benchmarking and error mitigation protocols.
Pauli Measurements Are Near-Optimal for Pure State Tomography

Summarize this article with:

Quantum Physics arXiv:2601.04444 (quant-ph) [Submitted on 7 Jan 2026] Title:Pauli Measurements Are Near-Optimal for Pure State Tomography Authors:Sabee Grewal, Meghal Gupta, William He, Aniruddha Sen, Mihir Singhal View a PDF of the paper titled Pauli Measurements Are Near-Optimal for Pure State Tomography, by Sabee Grewal and 3 other authors View PDF Abstract:We give an algorithm for pure state tomography with near-optimal copy complexity using single-qubit measurements. Specifically, given $\widetilde{O}(2^n/\epsilon)$ copies of an unknown pure $n$-qubit state $\lvert\psi\rangle$, the algorithm performs only \textit{nonadaptive Pauli measurements}, runs in time $\mathrm{poly}(2^n,1/\epsilon)$, and outputs $\lvert \widehat{\psi} \rangle$ that has fidelity $1-\epsilon$ with $\lvert \psi \rangle$ with high probability. This improves upon the previous best copy complexity bound of $\widetilde{O}(3^n/\epsilon)$. Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2601.04444 [quant-ph] (or arXiv:2601.04444v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2601.04444 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Meghal Gupta [view email] [v1] Wed, 7 Jan 2026 23:16:37 UTC (26 KB) Full-text links: Access Paper: View a PDF of the paper titled Pauli Measurements Are Near-Optimal for Pure State Tomography, by Sabee Grewal and 3 other authorsView PDFTeX Source view license Current browse context: quant-ph new | recent | 2026-01 References & Citations INSPIRE HEP NASA ADSGoogle Scholar Semantic Scholar export BibTeX citation Loading... BibTeX formatted citation × loading... Data provided by: Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv (What is alphaXiv?) Links to Code Toggle CatalyzeX Code Finder for Papers (What is CatalyzeX?) DagsHub Toggle DagsHub (What is DagsHub?) GotitPub Toggle Gotit.pub (What is GotitPub?) Huggingface Toggle Hugging Face (What is Huggingface?) Links to Code Toggle Papers with Code (What is Papers with Code?) ScienceCast Toggle ScienceCast (What is ScienceCast?) Demos Demos Replicate Toggle Replicate (What is Replicate?) Spaces Toggle Hugging Face Spaces (What is Spaces?) Spaces Toggle TXYZ.AI (What is TXYZ.AI?) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower (What are Influence Flowers?) Core recommender toggle CORE Recommender (What is CORE?) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs. Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)

Read Original

Tags

quantum-hardware

Source Information

Source: arXiv Quantum Physics