Optimal manipulations with qubits: Universal quantum entanglers

BŮŽEK, Vladimír and M. HILLERY. Optimal manipulations with qubits: Universal quantum entanglers. Physical Review A. USA: American Physical Society, 2000, vol. 62, No 02, p. 2303-2313. ISSN 1050-2947.

Basic information

• Original name: Optimal manipulations with qubits: Universal quantum entanglers
• Authors: BŮŽEK, Vladimír and M. HILLERY.
• Edition: Physical Review A, USA, American Physical Society, 2000, 1050-2947.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10301 Atomic, molecular and chemical physics
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 2.831
• RIV identification code: RIV/00216224:14330/00:00002892
• Organization unit: Faculty of Informatics
• UT WoS: 000088683400028
• Keywords in English: STATES; CLONING; SEPARABILITY; INFORMATION; ENSEMBLES
• Tags: CLONING, ENSEMBLES, information, separability, STATES

Abstract

We analyze various scenarios for entangling two initially unentangled qubits. In particular, we propose an optimal universal entangler that entangles a qubit in unknown state \psi] with a qubit in a reference (known) state \0]. That is, our entangler generates the output state that is as close as possible to the pure (symmetrized) state (\psi]\0]+\0]\psi]). The most attractive feature of this entangling machine, is that the fidelity of its performance (i.e., the distance between the output and the ideally entangled-symmetrized state) does not depend on the input and takes the constant value F = (9 + 3 root 2)/14 similar or equal to 0.946. We also analyze how to optimally generate from a single qubit initially prepared in an unknown state \psi]) a two qubit entangled system, which is as close as possible to a Bell state (\psi]\psi(perpendicular to)]+\psi(perpendicular to)]\psi]), where [psi\psi(perpendicular to)] = 0.

Links

• GA201/98/0369, research and development project: Name: Informatika jako třetí metodologie

Investor: Czech Science Foundation, Informatics as the third methodology

• MSM 143300001, plan (intention): Name: Nesekvenční modely výpočtů - kvantové a souběžné distribuované modely výpočetních procesů

Investor: Ministry of Education, Youth and Sports of the CR, Non-sequential Models of Computing -- Quantum and Concurrent Distributed Models of Computing