Tsubasu Ichikawa: "Entanglement of Indistinguishable Particles"

Tsubasu Ichikawa
Department of Physics, Kinki University, Japan

Entanglement of Indistinguishable Particles

Entanglement, which causes correlation stronger than classical one, plays a central role in quantum information science and foundation of quantum mechanics. For distinguishable par-ticles, the theoretical formulation of entanglement is well-established and utilized as an im-portant building block of theoretical works. On the other hand, for indistinguishable particles, we have no formulation as rigid as that for distinguishable particles.
In this seminar, I talk about our formulation of the entanglement of indistinguishable particles. First, I point out that the entanglement of distinguishable particles is formulated on the basis of tensor product structure (TPS) of state space, which is not inherent for that of indistin-guishable particles, because of (anti-)symmetrization. Second, I explain our method to im-plement TPS in the state space of indistinguishable particles. This is done by introducing a "measurement setup", which is represented as a set of orthogonal subspaces of one-particle state space. Third, I show implications of our formulation by various examples. We find that entanglement is relative to our choice of the measurement setups. Also, by this relative na-ture, we observe that our formulation reconciles former different approaches on this topic.