Sequential Implementation of Global Quantum Operations

We study the possibility for a global unitary applied on an arbitrary number of qubits to be decomposed in a sequential unitary procedure, where an ancillary system is allowed to interact only once with each qubit. We prove that sequential unitary decompositions are in general impossible for genuine...

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Detalles Bibliográficos
Autores: Lamata, L., León, J., Pérez García, David, Salgado, D., Solano, E.
Tipo de recurso: artículo
Fecha de publicación:2008
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/50305
Acceso en línea:https://hdl.handle.net/20.500.14352/50305
Access Level:acceso abierto
Palabra clave:530.145
Teoría de los quanta
2210.23 Teoría Cuántica
Descripción
Sumario:We study the possibility for a global unitary applied on an arbitrary number of qubits to be decomposed in a sequential unitary procedure, where an ancillary system is allowed to interact only once with each qubit. We prove that sequential unitary decompositions are in general impossible for genuine entangling operations, even with an infinite-dimensional ancilla, being the controlled-NOT gate a paradigmatic example. Nevertheless, we find particular nontrivial operations in quantum information that can be performed in a sequential unitary manner, as is the case of quantum error correction and quantum cloning.