"Novotn\u00FD, Jaroslav" . "21340" . "The structure is investigated of all completely positive quantum operations that transform pure two-qubit input states of a given degree of entanglement in a covariant way. Special cases thereof are quantum NOT operations which transform entangled pure two-qubit input states of a given degree of entanglement into orthogonal states in an optimal way. Based on our general analysis all covariant optimal two-qubit quantum NOT operations are determined. In particular, it is demonstrated that only in the case of maximally entangled input states can these quantum NOT operations be performed perfectly."@en . "The structure is investigated of all completely positive quantum operations that transform pure two-qubit input states of a given degree of entanglement in a covariant way. Special cases thereof are quantum NOT operations which transform entangled pure two-qubit input states of a given degree of entanglement into orthogonal states in an optimal way. Based on our general analysis all covariant optimal two-qubit quantum NOT operations are determined. In particular, it is demonstrated that only in the case of maximally entangled input states can these quantum NOT operations be performed perfectly." . "Physical Review A" . . "maps; optimal cloning; pure states"@en . . "[6280DA533E0D]" . . "Completely Positive Covariant two-Qubit Quantum Processes and Optimal Quantum NOT Operations for Entangled Qubit Pairs"@en . "Completely Positive Covariant two-Qubit Quantum Processes and Optimal Quantum NOT Operations for Entangled Qubit Pairs" . . . "0" . . "Completely Positive Covariant two-Qubit Quantum Processes and Optimal Quantum NOT Operations for Entangled Qubit Pairs"@en . "RIV/68407700:21340/06:04121607!RIV07-GA0-21340___" . "RIV/68407700:21340/06:04121607" . . . . "73" . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . "Jex, Igor" . . "12"^^ . "1050-2947" . . "3"^^ . . . . . "2"^^ . "Zcela positvn\u00ED kovariantn\u00ED 2-qubitov\u00E9 kvantov\u00E9 procesy and optim\u00E1ln\u00ED kvantov\u00E9 NOT operace for entanglovan\u00E9 p\u00E1ry qubit\u016F"@cs . "062311;062311" . "Zcela positvn\u00ED kovariantn\u00ED 2-qubitov\u00E9 kvantov\u00E9 procesy and optim\u00E1ln\u00ED kvantov\u00E9 NOT operace for entanglovan\u00E9 p\u00E1ry qubit\u016F"@cs . . "Completely Positive Covariant two-Qubit Quantum Processes and Optimal Quantum NOT Operations for Entangled Qubit Pairs" . "469380" . "P(GA202/04/2101), P(LC06002)" . . "Studujeme strukturu vsech uplne pozitivnich kvantovych operaci ktere prevadeji vstupni stav s danym provazanim na vystupni stav kovariantnim zpusobem. Specialnim pripadem takoveho zabrazeni je kvantova NOT operace, ktera transformuje optimalne provazany dvou qubitovy stav na jeho ortogonalni komplement. Na zaklade obecne analyzy procesu je podana uplna klasifikace NOT operaci a je ukazano, ze naprosto verna muze byt NOT operace jenom pro maximalne provazane stavy."@cs . "Alber, G." .