Symmetric entanglement classes for n qubits
Abstract
Permutation-symmetric n qubit pure states can be represented by n points on the surface of the unit sphere by means of the Majorana representation. Here this representation is employed to characterize and compare the three entanglement classification schemes LOCC, SLOCC and the Degeneracy Configuration. Symmetric SLOCC operations are found to be described by Mobius transformations, and an intuitive visualization of their freedoms is presented. For symmetric states of up to 5 qubits explicit forms of representative states for all SLOCC classes are derived. The symmetric 4 qubit entanglement classes are compared to the entanglement families introduced in [PRA 65, 052112 (2002)], and examples are given how the SLOCC-inequivalence of symmetric states can be quickly determined from known results about Mobius transformations.
Cite
@article{arxiv.1103.0271,
title = {Symmetric entanglement classes for n qubits},
author = {Martin Aulbach},
journal= {arXiv preprint arXiv:1103.0271},
year = {2011}
}
Comments
7 pages, 7 figures. Small improvements in contents and figures; submitted to journal. Parts of this paper were presented at AQIS 2010 (talk) and QIP 2011 (poster). During the completion of this paper I became aware of a similar work which also points out the relationship between SLOCC operations and Mobius transformations arXiv:1101.2828