On entanglement invariant for a double Jaynes–Cummings model
Man Zhong-Xiao, Yun‐Jie Xia · Chinese Physics B · 2008
In a recent paper [ Phys. Rev. A 76 042313 (2007)], Sainz and Bjork introduced an entanglement invariant E under evolution for a system of four qubits interacting through two isolated Jaynes–Cummings Hamiltonians. This paper proves that this entanglement invariant E is closely connected with the linear entropy between two independent subsystems.