Entanglement of Indistinguishable Particles Shared between Two Parties 论文

摘要

Using an operational definition we quantify the entanglement, ${E}_{P}$, between two parties who share an arbitrary pure state of $N$ indistinguishable particles. We show that ${E}_{P}\ensuremath{\le}{E}_{M}$, where ${E}_{M}$ is the bipartite entanglement calculated from the mode-occupation representation. Unlike ${E}_{M}$, ${E}_{P}$ is superadditive. For example, ${E}_{P}=0$ for any single-particle state, but the state $|1⟩|1⟩$, where both modes are split between the two parties, has ${E}_{P}=1/2$. We discuss how this relates to quantum correlations between particles, for both fermions and bosons.