{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T01:14:45Z","timestamp":1773278085268,"version":"3.50.1"},"reference-count":37,"publisher":"Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften","license":[{"start":{"date-parts":[[2021,9,28]],"date-time":"2021-09-28T00:00:00Z","timestamp":1632787200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Swiss National Science Fundation","award":["P2GEP2 194800"],"award-info":[{"award-number":["P2GEP2 194800"]}]}],"content-domain":{"domain":["quantum-journal.org"],"crossmark-restriction":false},"short-container-title":["Quantum"],"abstract":"<jats:p>Multiple observers who independently harvest nonclassical correlations from a single physical system share the system's ability to enable quantum correlations. We show that any number of independent observers can share the preparation contextual outcome statistics enabled by state ensembles in quantum theory. Furthermore, we show that even in the presence of any amount of white noise, there exists quantum ensembles that enable such shared preparation contextuality. The findings are experimentally realised by applying sequential unsharp measurements to an optical qubit ensemble which reveals three shared demonstrations of preparation contextuality.<\/jats:p>","DOI":"10.22331\/q-2021-09-28-551","type":"journal-article","created":{"date-parts":[[2021,9,28]],"date-time":"2021-09-28T13:23:16Z","timestamp":1632835396000},"page":"551","update-policy":"https:\/\/doi.org\/10.22331\/q-crossmark-policy-page","source":"Crossref","is-referenced-by-count":27,"title":["Noise-robust preparation contextuality shared between any number of observers via unsharp measurements"],"prefix":"10.22331","volume":"5","author":[{"given":"Hammad","family":"Anwer","sequence":"first","affiliation":[{"name":"Department of Physics, Stockholm University, S-10691 Stockholm, Sweden"}]},{"given":"Natalie","family":"Wilson","sequence":"additional","affiliation":[{"name":"Department of Physics, Stockholm University, S-10691 Stockholm, Sweden"}]},{"given":"Ralph","family":"Silva","sequence":"additional","affiliation":[{"name":"Institute for Theoretical Physics, ETH Zurich, Switzerland"}]},{"given":"Sadiq","family":"Muhammad","sequence":"additional","affiliation":[{"name":"Department of Physics, Stockholm University, S-10691 Stockholm, Sweden"}]},{"given":"Armin","family":"Tavakoli","sequence":"additional","affiliation":[{"name":"D\u00e9partement de Physique Appliqu\u00e9e, Universit\u00e9 de Gen\u00e8ve, CH-1211 Gen\u00e8ve, Switzerland"},{"name":"Institute for Quantum Optics and Quantum Information - IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria"},{"name":"Institute for Atomic and Subatomic Physics, Vienna University of Technology, 1020 Vienna, Austria"}]},{"given":"Mohamed","family":"Bourennane","sequence":"additional","affiliation":[{"name":"Department of Physics, Stockholm University, S-10691 Stockholm, Sweden"}]}],"member":"9598","published-online":{"date-parts":[[2021,9,28]]},"reference":[{"key":"0","doi-asserted-by":"publisher","unstructured":"C. A. Fuchs, and A. Peres, Quantum-state disturbance versus information gain: Uncertainty relations for quantum information Phys. Rev. A 53, 2038 (1996).","DOI":"10.1103\/PhysRevA.53.2038"},{"key":"1","doi-asserted-by":"publisher","unstructured":"R. Gallego, L. E. W\u00fcrflinger, R. Chaves, A. Ac\u00edn, M. Navascu\u00e9s, Nonlocality in sequential correlation scenarios, New J. Phys. 16, 033037 (2014).","DOI":"10.1088\/1367-2630\/16\/3\/033037"},{"key":"2","doi-asserted-by":"publisher","unstructured":"C. Budroni, T. Moroder, M. Kleinmann, and O. G\u00fchne, Bounding Temporal Quantum Correlations, Phys. Rev. Lett. 111, 020403 (2013).","DOI":"10.1103\/PhysRevLett.111.020403"},{"key":"3","doi-asserted-by":"publisher","unstructured":"R. Silva, N. Gisin, Y. Guryanova, and S. Popescu, Multiple Observers Can Share the Nonlocality of Half of an Entangled Pair by Using Optimal Weak Measurements, Phys. Rev. Lett. 114, 250401 (2015).","DOI":"10.1103\/PhysRevLett.114.250401"},{"key":"4","doi-asserted-by":"publisher","unstructured":"A. Tavakoli, A. Cabello, Quantum predictions for an unmeasured system cannot be simulated with a finite-memory classical system, Phys. Rev. A 97, 032131 (2018).","DOI":"10.1103\/PhysRevA.97.032131"},{"key":"5","doi-asserted-by":"publisher","unstructured":"P. J. Brown and R. Colbeck Arbitrarily Many Independent Observers Can Share the Nonlocality of a Single Maximally Entangled Qubit Pair, Phys. Rev. Lett. 125, 090401 (2020).","DOI":"10.1103\/PhysRevLett.125.090401"},{"key":"6","doi-asserted-by":"publisher","unstructured":"F. J. Curchod, M. Johansson, R. Augusiak, M. J. Hoban, P. Wittek, and A. Ac\u00edn, Unbounded randomness certification using sequences of measurements, Phys. Rev. A 95, 020102(R) (2017).","DOI":"10.1103\/PhysRevA.95.020102"},{"key":"7","doi-asserted-by":"publisher","unstructured":"B. Coyle, M. J. Hoban, and E. Kashefi, One-Sided Device-Independent Certification of Unbounded Random Numbers, EPTCS 273, 14-26 (2018).","DOI":"10.4204\/EPTCS.273.2"},{"key":"8","doi-asserted-by":"publisher","unstructured":"G. Foletto, L. Calderaro, A. Tavakoli, M. Schiavon, F. Picciariello, A. Cabello, P. Villoresi, and G. Vallone, Experimental Certification of Sustained Entanglement and Nonlocality after Sequential Measurements, Phys. Rev. Applied 13, 044008 (2020).","DOI":"10.1103\/PhysRevApplied.13.044008"},{"key":"9","doi-asserted-by":"publisher","unstructured":"M. Schiavon, L. Calderaro, M. Pittaluga, G. Vallone, and P. Villoresi, Three-observer Bell inequality violation on a two-qubit entangled state, Quantum Sci. Technol. 2 015010 (2017).","DOI":"10.1088\/2058-9565\/aa62be"},{"key":"10","doi-asserted-by":"publisher","unstructured":"M-J. Hu, Z-Y. Zhou, X-M. Hu, C-F. Li, G-C. Guo, and Y-S. Zhang, Observation of non-locality sharing among three observers with one entangled pair via optimal weak measurement, npj Quantum Information 4, 63 (2018).","DOI":"10.1038\/s41534-018-0115-x"},{"key":"11","doi-asserted-by":"publisher","unstructured":"A. Bera, S. Mal, A. Sen De, and U. Sen, Witnessing bipartite entanglement sequentially by multiple observers, Phys. Rev. A 98, 062304 (2018).","DOI":"10.1103\/PhysRevA.98.062304"},{"key":"12","doi-asserted-by":"publisher","unstructured":"S. Sasmal, D. Das, S. Mal, and A.S. Majumdar, Steering a single system sequentially by multiple observers, Phys. Rev. A 98, 012305 (2018).","DOI":"10.1103\/PhysRevA.98.012305"},{"key":"13","doi-asserted-by":"publisher","unstructured":"A. Shenoy H, S. Designolle, F. Hirsch, R. Silva, N. Gisin, and N. Brunner, Unbounded sequence of observers exhibiting Einstein-Podolsky-Rosen steering, Phys. Rev. A 99, 022317 (2019).","DOI":"10.1103\/PhysRevA.99.022317"},{"key":"14","doi-asserted-by":"publisher","unstructured":"K. Mohan. A. Tavakoli, and N. Brunner, Sequential random access codes and self-testing of quantum measurement instruments, New J. Phys. 21 083034 (2019).","DOI":"10.1088\/1367-2630\/ab3773"},{"key":"15","doi-asserted-by":"publisher","unstructured":"N. Miklin, J. Borkala, and M. Pawlowski, Semi-device-independent self-testing of unsharp measurements, Phys. Rev. Research 2, 033014 (2020).","DOI":"10.1103\/PhysRevResearch.2.033014"},{"key":"16","doi-asserted-by":"publisher","unstructured":"H. Anwer, S. Muhammad, W. Cherifi, N. Miklin, A. Tavakoli, and M. Bourennane, Experimental Characterization of Unsharp Qubit Observables and Sequential Measurement Incompatibility via Quantum Random Access Codes, Phys. Rev. Lett. 125, 080403 (2020).","DOI":"10.1103\/PhysRevLett.125.080403"},{"key":"17","doi-asserted-by":"publisher","unstructured":"G. Foletto, L. Calderaro, G. Vallone, and P. Villoresi, Experimental demonstration of sequential quantum random access codes, Phys. Rev. Research 2, 033205 (2020).","DOI":"10.1103\/PhysRevResearch.2.033205"},{"key":"18","doi-asserted-by":"publisher","unstructured":"R. W. Spekkens, Contextuality for preparations, transformations, and unsharp measurements Phys. Rev. A 71, 052108 (2005).","DOI":"10.1103\/PhysRevA.71.052108"},{"key":"19","doi-asserted-by":"publisher","unstructured":"R. W. Spekkens, Negativity and Contextuality are Equivalent Notions of Nonclassicality, Phys. Rev. Lett. 101, 020401 (2008).","DOI":"10.1103\/PhysRevLett.101.020401"},{"key":"20","doi-asserted-by":"publisher","unstructured":"R. W. Spekkens, D. H. Buzacott, A. J. Keehn, B. Toner, and G. J. Pryde, Preparation Contextuality Powers Parity-Oblivious Multiplexing Phys. Rev. Lett. 102, 010401 (2009).","DOI":"10.1103\/PhysRevLett.102.010401"},{"key":"21","doi-asserted-by":"publisher","unstructured":"M. S. Leifer, and O. J. E. Maroney, Maximally Epistemic Interpretations of the Quantum State and Contextuality, Phys. Rev. Lett. 110, 120401 (2013).","DOI":"10.1103\/PhysRevLett.110.120401"},{"key":"22","doi-asserted-by":"publisher","unstructured":"M. Banik, S. S. Bhattacharya, A. Mukherjee, A. Roy, A. Ambainis, and A. Rai, Limited preparation contextuality in quantum theory and its relation to the Cirel'son bound, Phys. Rev. A 92, 030103(R) (2015).","DOI":"10.1103\/PhysRevA.92.030103"},{"key":"23","doi-asserted-by":"publisher","unstructured":"S. Ghorai, A. K. Pan, Optimal quantum preparation contextuality in an n-bit parity-oblivious multiplexing task Phys. Rev. A 98, 032110 (2018).","DOI":"10.1103\/PhysRevA.98.032110"},{"key":"24","doi-asserted-by":"publisher","unstructured":"A. Tavakoli and R. Uola, Measurement incompatibility and steering are necessary and sufficient for operational contextuality, Phys. Rev. Research 2, 013011 (2020).","DOI":"10.1103\/PhysRevResearch.2.013011"},{"key":"25","doi-asserted-by":"publisher","unstructured":"D. Saha, and A. Chaturvedi, Preparation contextuality: the ground of quantum communication advantage, Phys. Rev. A 100, 022108 (2019).","DOI":"10.1103\/PhysRevA.100.022108"},{"key":"26","doi-asserted-by":"publisher","unstructured":"A. Tavakoli, E. Zambrini Cruzeiro, R. Uola, and A. A. Abbott, Bounding and Simulating Contextual Correlations in Quantum Theory, PRX Quantum 2, 020334 (2021).","DOI":"10.1103\/PRXQuantum.2.020334"},{"key":"27","doi-asserted-by":"publisher","unstructured":"A. Chaturvedi, M. Farkas, and V. Wright, Characterising and bounding the set of quantum behaviours in contextuality scenarios, Quantum 5, 484 (2021).","DOI":"10.22331\/q-2021-06-29-484"},{"key":"28","doi-asserted-by":"publisher","unstructured":"A. Hameedi, A. Tavakoli, B. Marques, and M. Bourennane, Communication games reveal preparation contextuality, Phys. Rev. Lett. 119, 220402 (2017).","DOI":"10.1103\/PhysRevLett.119.220402"},{"key":"29","doi-asserted-by":"publisher","unstructured":"M. D. Mazurek, M. F. Pusey, R. Kunjwal, K. J. Resch, and R. W. Spekkens, An experimental test of noncontextuality without unphysical idealizations, Nature Communications 7, 11780 (2016).","DOI":"10.1038\/ncomms11780"},{"key":"30","doi-asserted-by":"crossref","unstructured":"S. Kochen, and E. P. Specker, The Problem of Hidden Variables in Quantum Mechanics, Indiana University Mathematics Journal, 17, 59 (1967).","DOI":"10.1512\/iumj.1968.17.17004"},{"key":"31","doi-asserted-by":"publisher","unstructured":"N. Harrigan, and R. W. Spekkens, Einstein, Incompleteness, and the Epistemic View of Quantum States, Found Phys (2010) 40, 125 (2010).","DOI":"10.1007\/s10701-009-9347-0"},{"key":"32","doi-asserted-by":"publisher","unstructured":"A. Ambainis, A. Nayak, A. Ta-Shma, U. Vazirani, Dense quantum coding and a lower bound for 1-way quantum automata, Proceedings of the 31st Annual ACM Symposium on Theory of Computing (STOC'99), 376-383 (1999).","DOI":"10.1145\/301250.301347"},{"key":"33","doi-asserted-by":"publisher","unstructured":"A. Tavakoli, A. Hameedi, B. Marques, and M. Bourennane, Quantum random access codes using single d-Level systems, Phys. Rev. Lett. 114, 170502 (2015).","DOI":"10.1103\/PhysRevLett.114.170502"},{"key":"34","doi-asserted-by":"publisher","unstructured":"A. Chailloux, I. Kerenidis, S. Kundu, and J. Sikora, Optimal bounds for parity-oblivious random access codes, New J. Phys. 18, 045003 (2016).","DOI":"10.1088\/1367-2630\/18\/4\/045003"},{"key":"35","unstructured":"One could alternatively consider the Bobs' measurement devices inducing the noise. However, this is less detrimental than noisy preparations. The reason is that if Alice's preparations are noisy the correlations due to all Bobs' measurements are weaker, whereas if instead one (or many) of the Bobs sometimes fail to perform the intended measurement, the state relayed to the next Bob retains a higher degree of coherence and leads to him observering stronger correlations."},{"key":"36","doi-asserted-by":"publisher","unstructured":"A. Kumari and A. K. Pan, Sharing nonlocality and nontrivial preparation contextuality using the same family of Bell expressions, Phys. Rev. A 100, 062130 (2019).","DOI":"10.1103\/PhysRevA.100.062130"}],"container-title":["Quantum"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/quantum-journal.org\/papers\/q-2021-09-28-551\/pdf\/","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2021,9,28]],"date-time":"2021-09-28T13:23:20Z","timestamp":1632835400000},"score":1,"resource":{"primary":{"URL":"https:\/\/quantum-journal.org\/papers\/q-2021-09-28-551\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,28]]},"references-count":37,"URL":"https:\/\/doi.org\/10.22331\/q-2021-09-28-551","archive":["CLOCKSS"],"relation":{},"ISSN":["2521-327X"],"issn-type":[{"value":"2521-327X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,9,28]]},"article-number":"551"}}