Entanglement dynamics of double Jaynes-Cummings interaction model based   on geometric invariants
  We investigate entanglement dynamics and properties of double Jaynes-Cummings model. In particular we study the dynamics of double Jaynes-Cummings model based on geometric invariants for four qubits. We show that these geometric invariants provide us with useful information about different types of entanglement during the quantum evolution of the system. 
Hoshang Heydari and Duy Hoang
quant-ph