Three-qubit dynamics of entanglement in magnetic field
  A closed system of the equations for the local Bloch vectors and spin correlation functions is obtained by decomplexification of the Liouville-von Neumann equation for three magnetic qubits with the exchange interaction, that takes place in an arbitrary time-dependent external magnetic field. The numerical comparative analysis of entanglement is carried out depending on initial conditions and the magnetic field modulation. The present study may be useful for analysis of interference experiments and in the field of quantum computing. 
E. A. Ivanchenko