We experimentally test the recently predicted anisotropic invariance properties of pure three-qubit states, via generation and measurement of polarisation-path entangled three-qubit states. These properties do not require aligned reference frames and can be determined from measurements on any two of the qubits. They have several applications, such as a universal ordering of pairwise quantum correlations, strong monogamy relations for Bell inequalities and quantum steering, and a complementarity relation for Bell nonlocality versus 3-tangle, some of which we also test. The results indicate that anisotropic invariance, together with the three qubit Bloch vector lengths, can provide a robust and complete set of invariants for such states under local unitary transformations.
@article{arxiv.1811.08643,
title = {Experimental Verification of Anisotropic Invariance for Three-Qubit States},
author = {Jie Zhu and Meng-Jun Hu and Shuming Cheng and Michael J. W. Hall and Chuan-Feng Li and Guang-Can Guo and Yong-Sheng Zhang},
journal= {arXiv preprint arXiv:1811.08643},
year = {2019}
}