Seminario Q-Math

Quantum networks cannot generate graph states with high fidelity

Ponente:  Zhen-Peng Xu (Universität Siegen)
Fecha:  viernes 23 de septiembre de 2022 - 13:00
Lugar:  Room 2.2.D08, Universidad Carlos III de Madrid


Quantum networks lead to novel notions of locality and correlations which are not well understood. An important problem concerns the question which states can be experimentally prepared with a given network structure and which not. By exploiting the inflation technique and symmetry analysis, we prove that all multi-qubit graph states arising from a connected graph cannot originate from any bipartite network. Moreover, the fidelity of a multi-qubit graph state and any network state cannot exceed \(9/10\). Similar results can also be established for a large class of multi-qudit graph states. More specifically, the fidelity of any dimensional graph state with constant multiplicities and states prepared in a bipartite network cannot exceed \(0.95495\).