Optimal entanglement witnesses for qubits and qutrits

Journal Article · Tue Nov 15 00:00:00 EST 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.72.0· OSTI ID:20786483

Bertlmann, Reinhold A; Durstberger, Katharina; Hiesmayr, Beatrix C; Krammer, Philipp ^[1]

---

1. Institute for Theoretical Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria)

We study the connection between the Hilbert-Schmidt measure of entanglement (that is the minimal distance of an entangled state to the set of separable states) and entanglement witness in terms of a generalized Bell inequality which distinguishes between entangled and separable states. A method for checking the nearest separable state to a given entangled one is presented. We illustrate the general results by considering isotropic states, in particular two-qubit and two-qutrit states--and their generalizations to arbitrary dimensions--where we calculate the optimal entanglement witnesses explicitly.

• OSTI ID: 20786483
• Journal Information: Physical Review. A, Vol. 72, Issue 5; Other Information: DOI: 10.1103/PhysRevA.72.052331; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BELL THEOREM
DISTANCE
ENERGY LEVELS
QUANTUM COMPUTERS
QUANTUM ENTANGLEMENT
QUANTUM MECHANICS
QUBITS