The reduction of the closest disentangled states

Analytical formula connecting entangled state and the closest disentangled state

The separable state closest to a given entangled state in the relative entropy measure is called the closest disentangled state. We provide an analytical formula connecting the entangled state and the closest disentangled state in two qubits. Using this formula, when any disentangled state ($σ$) located at the entangle-disentangle boundary is given, entangled states to which $σ$ is closest can be obtained analytically. Further, this formula naturally defines the direction normal to the boundary surface. The direction is uniquely determined by $σ$ in almost all cases.

最近可及对称性约化：哈密顿量插值分析工具

Closest Accessible Symmetry reduction: a tool for Hamiltonian interpolation analysis

提出基于可及对称性概念的方法，通过投影到最近对称性扇区分析哈密顿量插值谱，捕捉量子相变特征并估计其位置。

Remarks on entanglement measures and non-local state distinguishability

We investigate the properties of three entanglement measures that quantify the statistical distinguishability of a given state with the closest disentangled state that has the same reductions as the primary state. In particular, we concentrate on the relative entropy of entanglement with reversed entries. We show that this quantity is an entanglement monotone which is strongly additive, thereby demonstrating that monotonicity under local quantum operations and strong additivity are compatible in principle. In accordance with the presented statistical interpretation which is provided, this enta…