Devi, ARU;
Prabhu, R;
Rajagopal, AK;
(2007)
Characterizing multiparticle entanglement in symmetric N-qubit states via negativity of covariance matrices.
Phys. Rev. Lett.
, 98
(6)
, Article 060501. 10.1103/PhysRevLett.98.060501.
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Abstract
We show that higher order inter-group covariances involving even number of qubits are necessarily positive semidefinite for N qubit separable states, which are completely symmetric under permutations of the qubits. This identification leads to a family of sufficient conditions of inseparability based on the negativity of 2kth order inter-group covariance matrices of symmetric N-qubit systems. These conditions have a simple structure and detect entanglement in all even partitions of the symmetric multiqubit system. The observables involved are feasible experimental quantities and do not demand full state determination through quantum state tomography.
| Type: | Article |
|---|---|
| Title: | Characterizing multiparticle entanglement in symmetric N-qubit states via negativity of covariance matrices |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1103/PhysRevLett.98.060501 |
| Publisher version: | http://dx.doi.org/10.1103/PhysRevLett.98.060501 |
| Language: | English |
| Additional information: | © 2007 The American Physical Society |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1303598 |
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