# Seminario

#### 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
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 $$0.95495$$.