Random quantum states and operations are of fundamental and practical interests. In this work, we investigate the entanglement properties of random hypergraph states, which generalize the notion of graph states by applying generalized controlled-phase gates on an initial reference product state. In particular, we study the two ensembles generated by random Controlled-Z(CZ) and Controlled-Controlled-Z(CCZ) gates, respectively. By applying tensor network representation and combinational counting, we analytically show that the average subsystem purity and entanglement entropy for the two ensembles feature the same volume law, but greatly differ in typicality, namely the purity fluctuation is small and universal for the CCZ ensemble while it is large for the CZ ensemble. We discuss the implications of these results for the onset of entanglement complexity and quantum chaos.
Dr. You Zhou now is a Research Fellow at Centre for Quantum Technologies, National University of Singapore, after a Postdoc at Harvard University, He got his Ph.D. of quantum information from Tsinghua University, and Bachelor of EE from Zhejiang University. You Zhou is interested in multipartite entanglement, quantum benchmarking, and the application to quantum (many-body) physics.
References: 1.arXiv:2110.07158 [quant-ph].