Entanglement and separability of two-qubit states on Minkowski space with compact support
- Departamento de Fisica, Universidade Federal de Sao Carlos, P.O. Box 676, Sao Carlos, CEP 13565-905, Sao Paulo (Brazil)
The entanglement properties of a two-qubit system are analyzed from the point of view of Lie algebras and geometry. We deal with 4x4 matrices belonging to a particular class having seven free parameters, constructed from the imposed symmetries on two-qubit states expanded in terms of a basis whose elements belong to a subalgebra of su(4). The entanglement or separability character of the state is determined and measured by analyzing the eigenvalues of an auxiliary matrix obtained from the original state after performing on it a nonunitary operation. In terms of its eigenvalues, we define two squared distances having a Minkowski metric, s{sup 2}=t{sup 2}-V(vector sign){sup 2}, which become a measure of the entanglement. The Minkowski metric is a signature of that class of two-qubit states (matrices) and also of the auxiliary matrices to be constructed. The squared distance is invariant by any unitary transformation on the two-qubit state. We illustrate the theory with examples.
- OSTI ID:
- 22093493
- Journal Information:
- Physical Review. A, Vol. 84, Issue 5; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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