We present an approach of constructing invariants under local unitary transformations for multipartite quantum systems. The invariants constructed in this way can be complement to that in [Science 340 (2013) 1205-1208]. Detailed examples are given to compute such invariant in detail. It is shown that these invariants can be used to detect the local unitary equivalence of degenerated quantum states.
@article{arxiv.1410.6254,
title = {Local Unitary Invariants for Multipartite Quantum Systems},
author = {Jing Wang and Ming Li and Shao-Ming Fei and Xianqing Li-Jost},
journal= {arXiv preprint arXiv:1410.6254},
year = {2015}
}