Entanglement and phase

Andreas Buchleitner, Carlos Viviescas, Markus Tiersch

Chao-Qian Pang, Mai-Lin Liang

A scheme is presented to generate an entangled atomic state, for which the quantum phase aects the atom atom entanglement when the atom interacts with external light elds.The quantum phase enhances the entanglement and extends the time that the system stays in stronger entanglement state or the phase makes the system more robust.It is also shown that the quantum phase is able to delay the entanglement sudden death and hasten the entanglement revival.

Mostafa Mansour, Mohammed Daoud A, Laila Bouhouch

We derive absolutely maximally entangled (AME) states from phase states for a multi-qudit system whose dynamics is governed by a two-qudit interaction Hamiltonian of Heisenberg type. AME states are characterized by being maximally entangled for all bipartitions of the multi-qudit system and present absolute multipartite entanglement. The key ingredient of this approach is the theory of phase states for finite-dimensional systems (qudits). We define further the unitary phase operators of [Formula: see text]-qudit systems and we give next the corresponding separable phase states. Using a qudit–qudit Hamiltonian acting as entangling operator on separable phase states, we generate entangled phase states. Finally, from the labeled entangled phase states, we derive the absolutely maximally entangled states.

Bei Zeng, Xie Chen, D. L. Zhou +1 more

Shunlong Luo, Zhengmin Zhang

Bing Xu, Xiaofei Qi, Jinchuan Hou

We discuss the behavior of positive linear maps in fermionic systems and then propose the phase partial transpose and the phase entanglement negativity. We show that every fermionic state which mixes local fermion-number parity must have nonvanishing nontrivial phase entanglement negativity, which gives an affirmative answer to a conjecture proposed by Shapourian and Ryu [Phys. Rev. A 99, 022310 (2019)]. In addition, we prove that the phase entanglement negativity is an entanglement monotone and establish some equalities and inequalities related to the phase entanglement negativity which, particularly, provide some upper bounds and lower bounds of the fermionic entanglement negativity. A more detailed discussion of the $(1+M)$-mode case is also presented, and our results generalize some known findings.