Unitary imaginary time evolution and ground state preparation using multi-copy protocols
Summarize this article with:
Quantum Physics arXiv:2603.11208 (quant-ph) [Submitted on 11 Mar 2026] Title:Unitary imaginary time evolution and ground state preparation using multi-copy protocols Authors:Tal Schwartzman, Torsten V. Zache, Hannes Pichler, H. R. Sadeghpour View a PDF of the paper titled Unitary imaginary time evolution and ground state preparation using multi-copy protocols, by Tal Schwartzman and 3 other authors View PDF HTML (experimental) Abstract:Efficient low-energy state preparation is a key objective in quantum computation and quantum simulation. Quantum imaginary-time evolution replaces real-time dynamics with imaginary-time dynamics, exponentially suppressing higher-energy eigenstates. We introduce deterministic unitary protocols that approximate imaginary-time evolution for ground-state preparation. The protocols require multiple copies of the system, real-time evolution under the system Hamiltonian, and controlled-SWAP operations (or more general SWAP-generated unitaries). We analyze two concrete circuit families: a tree architecture with provable polynomial-in-depth convergence but rapidly growing width, and a compact "hedge" architecture that achieves comparable accuracy with only polynomial width in a heuristic construction supported by numerics. We provide numerical evidence that mid-circuit post-selection can accelerate convergence with practical success probabilities. Separately, we demonstrate that circuit volume can be traded for the shot complexity of post-circuit observable estimation in the ground-state preparation setting. We outline concrete implementation of platform-specific routes, where multi-copy registers and SWAP-mediated couplings are natural, thereby illustrating how these hybrid analog-digital circuits can complement existing state-preparation methods in the near term. Comments: Subjects: Quantum Physics (quant-ph); High Energy Physics - Theory (hep-th); Atomic Physics (physics.atom-ph) Cite as: arXiv:2603.11208 [quant-ph] (or arXiv:2603.11208v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2603.11208 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Tal Schwartzman [view email] [v1] Wed, 11 Mar 2026 18:25:29 UTC (456 KB) Full-text links: Access Paper: View a PDF of the paper titled Unitary imaginary time evolution and ground state preparation using multi-copy protocols, by Tal Schwartzman and 3 other authorsView PDFHTML (experimental)TeX Source view license Current browse context: quant-ph new | recent | 2026-03 Change to browse by: hep-th physics physics.atom-ph 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?)