标题： 通过局部投影测量获得的相互作用玻色子气体双部分纯态中的纠缠 显示英文标题

标题： Entanglement in bipartite pure states of an interacting boson gas obtained by local projective measurements

摘要： 我们量化了通过在基态上进行粗粒度测量得到的Lieb-Liniger气体激发态的可提取纠缠，其中确定了气体两个互补连续部分之一中的玻色子数量。 从坐标Bethe假设中得到的数值精确结果表明，所得双部分纯态的冯·诺依曼熵随着排斥相互作用强度的增加而单调增加，并趋于不可渗透玻色子极限值。 我们还提供了证据，表明可以从给定分区中具有半个玻色子数的最可能投影态中提取最大的纠缠量。 我们的研究揭示了自由玻色子系统和自由费米子系统中纠缠性质的根本差异，前者的纠缠在投影后为零，而后者的纠缠（对应于不可渗透玻色子极限）则不为零。 显示英文摘要

摘要： We quantify the extractable entanglement of excited states of a Lieb-Liniger gas that are obtained from coarse-grained measurements on the ground state in which the boson number in one of two complementary contiguous partitions of the gas is determined. Numerically exact results obtained from the coordinate Bethe ansatz show that the von Neumann entropy of the resulting bipartite pure state increases monotonically with the strength of repulsive interactions and saturates to the impenetrable boson limiting value. We also present evidence indicating that the largest amount of entanglement can be extracted from the most probable projected state having half the number of bosons in a given partition. Our study points to a fundamental difference between the nature of the entanglement in free-bosonic and free-fermionic systems, with the entanglement in the former being zero after projection, while that in the latter (corresponding to the impenetrable boson limit) being non-zero.