2019/02/28 by Chon-Fai Kam, Ren-Bao Liu · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.101.032318
published as Phys. Rev. A 101, 032318 (2020)
arxiv created 2020/02/05 · arxiv updated 2020/03/18
Majorana stars, the 2j spin coherent states that are orthogonal to a spin-j state, offer a visualization of general quantum states and may disclose deep structures in quantum states and their evolutions. In particular, the genuine tripartite entanglement - the three-tangle of a symmetric three-qubit state, which can be mapped to a spin-3/2 state, is measured by the normalized product of the distance between the Majorana stars. However, the Majorana representation cannot applied to general non-symmetric n-qubit states. We show that after a series of SL(2,ℂ) transformations, non-symmetric three-qubit states can be transformed to symmetric three-qubit states, while at the same time the three-tangle is unchanged. Thus the genuine tripartite entanglement of general three-qubit states has the geometric representation of the associated Majorana stars. The symmetrization and hence the Majorana star representation of certain genuine high-order entanglement for more qubits are possible for some special states. In general cases, however, the constraints on the symmetrization may prevent the Majorana star representation of the genuine entanglement.