Classification of Multipartite Entanglement via Negativity Fonts

Partial transposition of state operator is a well known tool to detect quantum correlations between two parts of a composite system. In this letter, the global partial transpose (GPT) is linked to conceptually multipartite underlying structures in a state - the negativity fonts. If K-way negativity fonts with non zero determinants exist, then selective partial transposition of a pure state, involving K of the N qubits (K leq N) yields an operator with negative eigevalues, identifying K-body correlations in the state. Expansion of GPT interms of K-way partially transposed (KPT) operators reveals the nature of intricate intrinsic correlations in the state. Classification criteria for multipartite entangled states, based on underlying structure of global partial transpose of canonical state, are proposed. Number of N-partite entanglement types for an N qubit system is found to be 2^{N-1}-N+2, while the number of major entanglement classes is 2^{N-1}-1. Major classes for three and four qubit states are listed. Subclasses are determined by the number and type of negativity fonts in canonical state.Comment: 5 pages, No figures, Corrected typo

Quantum Group SU_{q}(2) and Pairing in Nuclei

A scheme for treating the pairing of nucleons in terms of generators of Quantum Group SU_{q}(2) is presented. The possible applications to nucleon pairs in a single orbit, multishell case, pairing vibrations and superconducting nuclei are discussed. The formalism for performing BCS calculations with q-deformed nucleon pairs is constructed and the role played by deformation parameter q analyzed in the context of nucleons in a single orbit and for Sn Isotopes.Comment: 6 Pages, No figures, To be published in Proceedings of International Conference "Geometrical Aspects of Quantum Fields", Londrina PR, April 2000, World Scientifi

Four-tangle for pure states

An expression for four-tangle is obtained by examining the negativity fonts present in a four-way partial transpose under local unitary operations. An alternate derivation of three tangle is also given.Comment: 5 pages, No figure

Genuine Four Tangle for Four Qubit States

We report a four qubit polynomial invariant that quantifies genuine four-body correlations. The four qubit invariants are obtained from transformation properties of three qubit invariants under a local unitary on the fourth qubit.Comment: 03 pages, This short communication is a contribution to the proceedings of QCMC 2012 held in Vienna, Austria, July 30th to August 3rd 201

Unitary Invariants and Classification of Four-Qubit States via Negativity Fonts

Local unitary invariance and the notion of negativity fonts are used as the principle tools to construct four qubit invariants of degree 8, 12, and 24. A degree 8 polynomial invariant that is non-zero on pure four qubit states with four-body correlations and zero on all other states, is identified. Classification of four qubit states into seven major classes, using criterion based on the nature of correlations, is discussed.Comment: 12 pages, revtex, Eq. 26 and other Typos correcte