{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,10]],"date-time":"2025-11-10T13:57:30Z","timestamp":1762783050989,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2024,1,13]],"date-time":"2024-01-13T00:00:00Z","timestamp":1705104000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["12175003","12361161602","U2330201"],"award-info":[{"award-number":["12175003","12361161602","U2330201"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"NSAF","award":["12175003","12361161602","U2330201"],"award-info":[{"award-number":["12175003","12361161602","U2330201"]}]},{"name":"Alibaba Group","award":["12175003","12361161602","U2330201"],"award-info":[{"award-number":["12175003","12361161602","U2330201"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Errors are common issues in quantum computing platforms, among which leakage is one of the most-challenging to address. This is because leakage, i.e., the loss of information stored in the computational subspace to undesired subspaces in a larger Hilbert space, is more difficult to detect and correct than errors that preserve the computational subspace. As a result, leakage presents a significant obstacle to the development of fault-tolerant quantum computation. In this paper, we propose an efficient and accurate benchmarking framework called leakage randomized benchmarking (LRB), for measuring leakage rates on multi-qubit quantum systems. Our approach is more insensitive to state preparation and measurement (SPAM) noise than existing leakage benchmarking protocols, requires fewer assumptions about the gate set itself, and can be used to benchmark multi-qubit leakages, which has not been achieved previously. We also extended the LRB protocol to an interleaved variant called interleaved LRB (iLRB), which can benchmark the average leakage rate of generic n-site quantum gates with reasonable noise assumptions. We demonstrate the iLRB protocol on benchmarking generic two-qubit gates realized using flux tuning and analyzed the behavior of iLRB under corresponding leakage models. Our numerical experiments showed good agreement with the theoretical estimations, indicating the feasibility of both the LRB and iLRB protocols.<\/jats:p>","DOI":"10.3390\/e26010071","type":"journal-article","created":{"date-parts":[[2024,1,15]],"date-time":"2024-01-15T08:52:03Z","timestamp":1705308723000},"page":"71","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Leakage Benchmarking for Universal Gate Sets"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3894-2979","authenticated-orcid":false,"given":"Bujiao","family":"Wu","sequence":"first","affiliation":[{"name":"Center on Frontiers of Computing Studies, Peking University, Beijing 100871, China"},{"name":"School of Computer Science, Peking University, Beijing 100871, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2667-1879","authenticated-orcid":false,"given":"Xiaoyang","family":"Wang","sequence":"additional","affiliation":[{"name":"Center on Frontiers of Computing Studies, Peking University, Beijing 100871, China"},{"name":"School of Physics, Peking University, Beijing 100871, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0205-6545","authenticated-orcid":false,"given":"Xiao","family":"Yuan","sequence":"additional","affiliation":[{"name":"Center on Frontiers of Computing Studies, Peking University, Beijing 100871, China"},{"name":"School of Computer Science, Peking University, Beijing 100871, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7466-8033","authenticated-orcid":false,"given":"Cupjin","family":"Huang","sequence":"additional","affiliation":[{"name":"Alibaba Quantum Laboratory, Alibaba Group USA, Bellevue, WA 98004, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9365-776X","authenticated-orcid":false,"given":"Jianxin","family":"Chen","sequence":"additional","affiliation":[{"name":"Alibaba Quantum Laboratory, Alibaba Group USA, Bellevue, WA 98004, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1184","DOI":"10.1038\/s41567-020-0992-8","article-title":"Efficient learning of quantum noise","volume":"16","author":"Harper","year":"2020","journal-title":"Nat. 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