{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T17:17:57Z","timestamp":1791911877060,"version":"4.3.4"},"reference-count":40,"publisher":"Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften","license":[{"start":{"date-parts":[[2023,8,8]],"date-time":"2023-08-08T00:00:00Z","timestamp":1691452800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Office of the Director of National Intelligence - Intelligence Advanced Research Projects Activity","award":["W911NF-16-1-0082"],"award-info":[{"award-number":["W911NF-16-1-0082"]}]},{"DOI":"10.13039\/100000183","name":"Army Research Office","doi-asserted-by":"crossref","award":["W911NF-21-1-0005"],"award-info":[{"award-number":["W911NF-21-1-0005"]}],"id":[{"id":"10.13039\/100000183","id-type":"DOI","asserted-by":"crossref"}]},{"name":"National Science Foundation","award":["OMA-2120757"],"award-info":[{"award-number":["OMA-2120757"]}]}],"content-domain":{"domain":["quantum-journal.org"],"crossmark-restriction":false},"short-container-title":["Quantum"],"abstract":"<jats:p>The Shor fault-tolerant error correction (FTEC) scheme uses transversal gates and ancilla qubits prepared in the cat state in syndrome extraction circuits to prevent propagation of errors caused by gate faults. For a stabilizer code of distance <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mi>d<\/mml:mi><\/mml:math> that can correct up to <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mi>t<\/mml:mi><mml:mo>=<\/mml:mo><mml:mo fence=\"false\" stretchy=\"false\">&amp;#x230A;<\/mml:mo><mml:mo stretchy=\"false\">(<\/mml:mo><mml:mi>d<\/mml:mi><mml:mo>&amp;#x2212;<\/mml:mo><mml:mn>1<\/mml:mn><mml:mo stretchy=\"false\">)<\/mml:mo><mml:mrow class=\"MJX-TeXAtom-ORD\"><mml:mo>\/<\/mml:mo><\/mml:mrow><mml:mn>2<\/mml:mn><mml:mo fence=\"false\" stretchy=\"false\">&amp;#x230B;<\/mml:mo><\/mml:math> errors, the traditional Shor scheme handles ancilla preparation and measurement faults by performing syndrome measurements until the syndromes are repeated <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mi>t<\/mml:mi><mml:mo>+<\/mml:mo><mml:mn>1<\/mml:mn><\/mml:math> times in a row; in the worst-case scenario, <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mo stretchy=\"false\">(<\/mml:mo><mml:mi>t<\/mml:mi><mml:mo>+<\/mml:mo><mml:mn>1<\/mml:mn><mml:msup><mml:mo stretchy=\"false\">)<\/mml:mo><mml:mn>2<\/mml:mn><\/mml:msup><\/mml:math> rounds of measurements are required. In this work, we improve the Shor FTEC scheme using an adaptive syndrome measurement technique. The syndrome for error correction is determined based on information from the differences of syndromes obtained from consecutive rounds. Our protocols that satisfy the strong and the weak FTEC conditions require no more than <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mo stretchy=\"false\">(<\/mml:mo><mml:mi>t<\/mml:mi><mml:mo>+<\/mml:mo><mml:mn>3<\/mml:mn><mml:msup><mml:mo stretchy=\"false\">)<\/mml:mo><mml:mn>2<\/mml:mn><\/mml:msup><mml:mrow class=\"MJX-TeXAtom-ORD\"><mml:mo>\/<\/mml:mo><\/mml:mrow><mml:mn>4<\/mml:mn><mml:mo>&amp;#x2212;<\/mml:mo><mml:mn>1<\/mml:mn><\/mml:math> rounds and <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mo stretchy=\"false\">(<\/mml:mo><mml:mi>t<\/mml:mi><mml:mo>+<\/mml:mo><mml:mn>3<\/mml:mn><mml:msup><mml:mo stretchy=\"false\">)<\/mml:mo><mml:mn>2<\/mml:mn><\/mml:msup><mml:mrow class=\"MJX-TeXAtom-ORD\"><mml:mo>\/<\/mml:mo><\/mml:mrow><mml:mn>4<\/mml:mn><mml:mo>&amp;#x2212;<\/mml:mo><mml:mn>2<\/mml:mn><\/mml:math> rounds, respectively, and are applicable to any stabilizer code. Our simulations of FTEC protocols with the adaptive schemes on hexagonal color codes of small distances verify that our protocols preserve the code distance, can increase the pseudothreshold, and can decrease the average number of rounds compared to the traditional Shor scheme. We also find that for the code of distance <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mi>d<\/mml:mi><\/mml:math>, our FTEC protocols with the adaptive schemes require no more than <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:mi>d<\/mml:mi><\/mml:math> rounds on average.<\/jats:p>","DOI":"10.22331\/q-2023-08-08-1075","type":"journal-article","created":{"date-parts":[[2023,8,8]],"date-time":"2023-08-08T13:47:26Z","timestamp":1691502446000},"page":"1075","update-policy":"https:\/\/doi.org\/10.22331\/q-crossmark-policy-page","source":"Crossref","is-referenced-by-count":22,"title":["Adaptive syndrome measurements for Shor-style error correction"],"prefix":"10.22331","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2865-0705","authenticated-orcid":false,"given":"Theerapat","family":"Tansuwannont","sequence":"first","affiliation":[{"name":"Duke Quantum Center, Duke University, Durham, NC 27701, USA"},{"name":"Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9502-3368","authenticated-orcid":false,"given":"Balint","family":"Pato","sequence":"additional","affiliation":[{"name":"Duke Quantum Center, Duke University, Durham, NC 27701, USA"},{"name":"Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7716-1425","authenticated-orcid":false,"given":"Kenneth R.","family":"Brown","sequence":"additional","affiliation":[{"name":"Duke Quantum Center, Duke University, Durham, NC 27701, USA"},{"name":"Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA"},{"name":"Department of Physics, Duke University, Durham, NC 27708, USA"},{"name":"Department of Chemistry, Duke University, Durham, NC 27708, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"9598","published-online":{"date-parts":[[2023,8,8]]},"reference":[{"key":"0","doi-asserted-by":"publisher","unstructured":"P.W. Shor. ``Fault-tolerant quantum computation&apos;&apos;. In Proceedings of 37th Conference on Foundations of Computer Science. Pages 56\u201365. (1996).","DOI":"10.1109\/SFCS.1996.548464"},{"key":"1","doi-asserted-by":"publisher","unstructured":"Dorit Aharonov and Michael Ben-Or. ``Fault-tolerant quantum computation with constant error rate&apos;&apos;. SIAM J. Comput. 38, 1207\u20131282 (2008).","DOI":"10.1137\/S0097539799359385"},{"key":"2","doi-asserted-by":"publisher","unstructured":"A Yu Kitaev. ``Quantum computations: algorithms and error correction&apos;&apos;. Russian Mathematical Surveys 52, 1191 (1997).","DOI":"10.1070\/RM1997v052n06ABEH002155"},{"key":"3","unstructured":"E. Knill, R. Laflamme, and W. Zurek. ``Threshold accuracy for quantum computation&apos;&apos; (1996). arXiv:quant-ph\/9610011."},{"key":"4","doi-asserted-by":"publisher","unstructured":"John Preskill. ``Reliable quantum computers&apos;&apos;. Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 454, 385\u2013410 (1998).","DOI":"10.1098\/rspa.1998.0167"},{"key":"5","doi-asserted-by":"publisher","unstructured":"Barbara M. Terhal and Guido Burkard. ``Fault-tolerant quantum computation for local non-markovian noise&apos;&apos;. Phys. Rev. A 71, 012336 (2005).","DOI":"10.1103\/PhysRevA.71.012336"},{"key":"6","doi-asserted-by":"publisher","unstructured":"Michael A. Nielsen and Christopher M. Dawson. ``Fault-tolerant quantum computation with cluster states&apos;&apos;. Phys. Rev. A 71, 042323 (2005).","DOI":"10.1103\/PhysRevA.71.042323"},{"key":"7","doi-asserted-by":"publisher","unstructured":"Panos Aliferis and Debbie W. Leung. ``Simple proof of fault tolerance in the graph-state model&apos;&apos;. Phys. Rev. A 73, 032308 (2006).","DOI":"10.1103\/PhysRevA.73.032308"},{"key":"8","doi-asserted-by":"publisher","unstructured":"Panos Aliferis, Daniel Gottesman, and John Preskill. ``Quantum accuracy threshold for concatenated distance-3 codes&apos;&apos;. Quantum Info. Comput. 6, 97\u2013165 (2006).","DOI":"10.26421\/QIC6.2-1"},{"key":"9","doi-asserted-by":"publisher","unstructured":"Andrew M. Steane. ``Overhead and noise threshold of fault-tolerant quantum error correction&apos;&apos;. Phys. Rev. A 68, 042322 (2003).","DOI":"10.1103\/PhysRevA.68.042322"},{"key":"10","doi-asserted-by":"publisher","unstructured":"Adam Paetznick and Ben W. Reichardt. ``Fault-tolerant ancilla preparation and noise threshold lower boudds for the 23-qubit golay code&apos;&apos;. Quantum Info. Comput. 12, 1034\u20131080 (2012).","DOI":"10.26421\/QIC12.11-12-10"},{"key":"11","doi-asserted-by":"publisher","unstructured":"Christopher Chamberland, Tomas Jochym-O&apos;Connor, and Raymond Laflamme. ``Overhead analysis of universal concatenated quantum codes&apos;&apos;. Phys. Rev. A 95, 022313 (2017).","DOI":"10.1103\/PhysRevA.95.022313"},{"key":"12","doi-asserted-by":"publisher","unstructured":"Ryuji Takagi, Theodore J. Yoder, and Isaac L. Chuang. ``Error rates and resource overheads of encoded three-qubit gates&apos;&apos;. Phys. Rev. A 96, 042302 (2017).","DOI":"10.1103\/PhysRevA.96.042302"},{"key":"13","unstructured":"Nicolas Delfosse and Ben W. Reichardt. ``Short shor-style syndrome sequences&apos;&apos; (2020). arXiv:2008.05051."},{"key":"14","unstructured":"Christof Zalka. ``Threshold estimate for fault tolerant quantum computation&apos;&apos; (1997). arXiv:quant-ph\/9612028."},{"key":"15","doi-asserted-by":"publisher","unstructured":"Ben W Reichardt. ``Fault-tolerant quantum error correction for Steane\u2019s seven-qubit color code with few or no extra qubits&apos;&apos;. Quantum Science and Technology 6, 015007 (2020).","DOI":"10.1088\/2058-9565\/abc6f4"},{"key":"16","doi-asserted-by":"publisher","unstructured":"Daniel Gottesman. ``Class of quantum error-correcting codes saturating the quantum hamming bound&apos;&apos;. Phys. Rev. A 54, 1862\u20131868 (1996).","DOI":"10.1103\/PhysRevA.54.1862"},{"key":"17","doi-asserted-by":"publisher","unstructured":"Daniel Gottesman. ``Stabilizer Codes and Quantum Error Correction&apos;&apos;. PhD thesis. California Institute of Technology. (1997).","DOI":"10.7907\/rzr7-dt72"},{"key":"18","doi-asserted-by":"publisher","unstructured":"Theerapat Tansuwannont and Debbie Leung. ``Achieving fault tolerance on capped color codes with few ancillas&apos;&apos;. PRX Quantum 3, 030322 (2022).","DOI":"10.1103\/PRXQuantum.3.030322"},{"key":"19","unstructured":"S. B. Bravyi and A. Yu. Kitaev. ``Quantum codes on a lattice with boundary&apos;&apos; (1998). arXiv:quant-ph\/9811052."},{"key":"20","doi-asserted-by":"publisher","unstructured":"H. Bombin and M. A. Martin-Delgado. ``Topological quantum distillation&apos;&apos;. Phys. Rev. Lett. 97, 180501 (2006).","DOI":"10.1103\/PhysRevLett.97.180501"},{"key":"21","doi-asserted-by":"publisher","unstructured":"David P. DiVincenzo and Panos Aliferis. ``Effective fault-tolerant quantum computation with slow measurements&apos;&apos;. Phys. Rev. Lett. 98, 020501 (2007).","DOI":"10.1103\/PhysRevLett.98.020501"},{"key":"22","doi-asserted-by":"publisher","unstructured":"Rui Chao and Ben W. Reichardt. ``Quantum error correction with only two extra qubits&apos;&apos;. Phys. Rev. Lett. 121, 050502 (2018).","DOI":"10.1103\/PhysRevLett.121.050502"},{"key":"23","doi-asserted-by":"publisher","unstructured":"Rui Chao and Ben W. Reichardt. ``Flag fault-tolerant error correction for any stabilizer code&apos;&apos;. PRX Quantum 1, 010302 (2020).","DOI":"10.1103\/PRXQuantum.1.010302"},{"key":"24","doi-asserted-by":"publisher","unstructured":"Christopher Chamberland and Michael E. Beverland. ``Flag fault-tolerant error correction with arbitrary distance codes&apos;&apos;. Quantum 2, 53 (2018).","DOI":"10.22331\/q-2018-02-08-53"},{"key":"25","doi-asserted-by":"publisher","unstructured":"Theerapat Tansuwannont, Christopher Chamberland, and Debbie Leung. ``Flag fault-tolerant error correction, measurement, and quantum computation for cyclic Calderbank-Shor-Steane codes&apos;&apos;. Phys. Rev. A 101, 012342 (2020).","DOI":"10.1103\/PhysRevA.101.012342"},{"key":"26","doi-asserted-by":"publisher","unstructured":"Christopher Chamberland, Aleksander Kubica, Theodore J Yoder, and Guanyu Zhu. ``Triangular color codes on trivalent graphs with flag qubits&apos;&apos;. New Journal of Physics 22, 023019 (2020).","DOI":"10.1088\/1367-2630\/ab68fd"},{"key":"27","doi-asserted-by":"publisher","unstructured":"Christopher Chamberland, Guanyu Zhu, Theodore J. Yoder, Jared B. Hertzberg, and Andrew W. Cross. ``Topological and subsystem codes on low-degree graphs with flag qubits&apos;&apos;. Phys. Rev. X 10, 011022 (2020).","DOI":"10.1103\/PhysRevX.10.011022"},{"key":"28","doi-asserted-by":"publisher","unstructured":"Theerapat Tansuwannont and Debbie Leung. ``Fault-tolerant quantum error correction using error weight parities&apos;&apos;. Phys. Rev. A 104, 042410 (2021).","DOI":"10.1103\/PhysRevA.104.042410"},{"key":"29","doi-asserted-by":"publisher","unstructured":"A. R. Calderbank and Peter W. Shor. ``Good quantum error-correcting codes exist&apos;&apos;. Phys. Rev. A 54, 1098\u20131105 (1996).","DOI":"10.1103\/PhysRevA.54.1098"},{"key":"30","doi-asserted-by":"publisher","unstructured":"Andrew Steane. ``Multiple-particle interference and quantum error correction&apos;&apos;. Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 452, 2551\u20132577 (1996).","DOI":"10.1098\/rspa.1996.0136"},{"key":"31","doi-asserted-by":"publisher","unstructured":"Cirq Developers. ``Cirq v1.1.0 - a Python library for writing, manipulating, and optimizing quantum circuits and running them against quantum computers and simulators&apos;&apos;. Zenodo (2022).","DOI":"10.5281\/zenodo.7465577"},{"key":"32","doi-asserted-by":"publisher","unstructured":"Craig Gidney. ``Stim: a fast stabilizer circuit simulator&apos;&apos;. Quantum 5, 497 (2021).","DOI":"10.22331\/q-2021-07-06-497"},{"key":"33","unstructured":"Balint Pato, Theerapat Tansuwannont, Shilin Huang, and Kenneth R. Brown. ``Optimization tools for distance-preserving flag fault-tolerant error correction&apos;&apos; (2023). arXiv:2306.12862."},{"key":"34","doi-asserted-by":"publisher","unstructured":"Michael A. Nielsen and Isaac L. Chuang. ``Quantum computation and quantum information: 10th anniversary edition&apos;&apos;. Cambridge University Press. (2010).","DOI":"10.1017\/CBO9780511976667"},{"key":"35","doi-asserted-by":"publisher","unstructured":"Adam Paetznick and Ben W. Reichardt. ``Universal fault-tolerant quantum computation with only transversal gates and error correction&apos;&apos;. Phys. Rev. Lett. 111, 090505 (2013).","DOI":"10.1103\/PhysRevLett.111.090505"},{"key":"36","doi-asserted-by":"publisher","unstructured":"Jonas T. Anderson, Guillaume Duclos-Cianci, and David Poulin. ``Fault-tolerant conversion between the Steane and Reed-Muller quantum codes&apos;&apos;. Phys. Rev. Lett. 113, 080501 (2014).","DOI":"10.1103\/PhysRevLett.113.080501"},{"key":"37","doi-asserted-by":"publisher","unstructured":"Hector Bombin. ``Gauge color codes: optimal transversal gates and gauge fixing in topological stabilizer codes&apos;&apos;. New Journal of Physics 17, 083002 (2015).","DOI":"10.1088\/1367-2630\/17\/8\/083002"},{"key":"38","doi-asserted-by":"publisher","unstructured":"Aleksander Kubica and Michael E. Beverland. ``Universal transversal gates with color codes: A simplified approach&apos;&apos;. Phys. Rev. A 91, 032330 (2015).","DOI":"10.1103\/PhysRevA.91.032330"},{"key":"39","doi-asserted-by":"publisher","unstructured":"Eric Dennis, Alexei Kitaev, Andrew Landahl, and John Preskill. ``Topological quantum memory&apos;&apos;. Journal of Mathematical Physics 43, 4452\u20134505 (2002).","DOI":"10.1063\/1.1499754"}],"container-title":["Quantum"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/quantum-journal.org\/papers\/q-2023-08-08-1075\/pdf\/","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2023,8,8]],"date-time":"2023-08-08T13:49:26Z","timestamp":1691502566000},"score":1,"resource":{"primary":{"URL":"https:\/\/quantum-journal.org\/papers\/q-2023-08-08-1075\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,8]]},"references-count":40,"URL":"https:\/\/doi.org\/10.22331\/q-2023-08-08-1075","archive":["CLOCKSS"],"relation":{},"ISSN":["2521-327X"],"issn-type":[{"value":"2521-327X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,8,8]]},"article-number":"1075"}}