{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2022,4,1]],"date-time":"2022-04-01T19:46:30Z","timestamp":1648842390743},"reference-count":15,"publisher":"World Scientific Pub Co Pte Lt","issue":"03","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Open Syst. Inf. Dyn."],"published-print":{"date-parts":[[2006,9]]},"abstract":"<jats:p> When standard methods of process (black-box) estimation are applied straightforwardly then it may happen that some sets of experimental data result in unphysical estimations of the corresponding channels (maps) describing the process. To prevent this problem, one can use the method of maximum likelihood (MML), which provides an efficient scheme for reconstruction of quantum channels. This scheme always results in estimations of channels that are fully physical, e.g. the corresponding maps are linear, positive and completely positive. To show this property, we use the MML for a derivation of physical approximations of truly unphysical operations. In particular, we analyze physical approximations of the universal-NOT gate, the quantum nonlinear polarization rotation and the map \u03c1 \u2192 \u03c1<jats:sup>2<\/jats:sup>. Given the result of MML, we examine retrospectively the quality of the experiment. Depending on the resulting value of the MML functional we can determine (physical) consistency of the input data. <\/jats:p>","DOI":"10.1007\/s11080-006-9005-3","type":"journal-article","created":{"date-parts":[[2006,8,31]],"date-time":"2006-08-31T06:34:30Z","timestamp":1157006070000},"page":"255-262","source":"Crossref","is-referenced-by-count":0,"title":["Estimation of Potentially Unphysical Maps"],"prefix":"10.1142","volume":"13","author":[{"given":"Martin","family":"Plesch","sequence":"first","affiliation":[{"name":"Research Center for Quantum Information, Slovak Academy of Sciences, D\u00fabravsk\u00e1 cesta 9, 845 11 Bratislava, Slovakia"},{"name":"Quniverse, L\u00ed\u0161\u010die \u00fadolie 116, 841 04 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M\u00e1rio","family":"Ziman","sequence":"additional","affiliation":[{"name":"Research Center for Quantum Information, Slovak Academy of Sciences, D\u00fabravsk\u00e1 cesta 9, 845 11 Bratislava, Slovakia"},{"name":"Faculty of Informatics, Masaryk University, Botanick\u00e1 68a, 602 00 Brno, Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vladim\u00edr","family":"Bu\u017eek","sequence":"additional","affiliation":[{"name":"Research Center for Quantum Information, Slovak Academy of Sciences, D\u00fabravsk\u00e1 cesta 9, 845 11 Bratislava, Slovakia"},{"name":"Abteilung f\u00fcr Quantenphysik, Universit\u00e4t Ulm, 89069 Ulm, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"\u0160telmachovi\u010d","sequence":"additional","affiliation":[{"name":"Research Center for Quantum Information, Slovak Academy of Sciences, D\u00fabravsk\u00e1 cesta 9, 845 11 Bratislava, Slovakia"},{"name":"Quniverse, L\u00ed\u0161\u010die \u00fadolie 116, 841 04 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"219","published-online":{"date-parts":[[2012,4,17]]},"reference":[{"key":"rf1","volume-title":"Quantum Computation and Quantum Information","author":"Nielsen M. A.","year":"2000"},{"key":"rf2","series-title":"Lecture Notes on Physics","volume-title":"Quantum Theory of Information and Computation","volume":"229","author":"Preskill J.","year":"1998"},{"key":"rf3","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.86.4195"},{"key":"rf4","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.78.390"},{"key":"rf5","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.58.1723"},{"key":"rf6","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.72.022106"},{"key":"rf7","doi-asserted-by":"publisher","DOI":"10.1017\/S0305004100009580"},{"key":"rf8","unstructured":"Z.\u00a0Hradil, Quantum Estimations: Theory and Experiment (Springer-Verlag, Berlin, 2004)\u00a0p. 63."},{"key":"rf9","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.60.R2626"},{"key":"rf10","doi-asserted-by":"publisher","DOI":"10.1038\/nature01093"},{"key":"rf11","doi-asserted-by":"publisher","DOI":"10.1088\/1464-4258\/2\/4\/313"},{"key":"rf12","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.63.020101"},{"key":"rf13","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.63.054104"},{"key":"rf15","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.59.4238"},{"key":"rf16","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.83.432"}],"container-title":["Open Systems &amp; Information Dynamics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.worldscientific.com\/doi\/pdf\/10.1007\/s11080-006-9005-3","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,8,7]],"date-time":"2019-08-07T00:31:27Z","timestamp":1565137887000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.worldscientific.com\/doi\/abs\/10.1007\/s11080-006-9005-3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2006,9]]},"references-count":15,"journal-issue":{"issue":"03","published-online":{"date-parts":[[2012,4,17]]},"published-print":{"date-parts":[[2006,9]]}},"alternative-id":["10.1007\/s11080-006-9005-3"],"URL":"https:\/\/doi.org\/10.1007\/s11080-006-9005-3","relation":{},"ISSN":["1230-1612","1793-7191"],"issn-type":[{"value":"1230-1612","type":"print"},{"value":"1793-7191","type":"electronic"}],"subject":[],"published":{"date-parts":[[2006,9]]}}}