  Quantum systems are the future candidates for computers and information
processing devices. Information about quantum states and processes may be
incomplete and scattered in these systems. We use a quantum version of Belief
Propagation(BP) Algorithm to integrate the distributed information. In this
algorithm the distributed information, which is in the form of density matrix,
can be approximated to local structures. The validity of this algorithm is
measured in comparison with Suzuki-Trotter(ST) method, using simulated
information. ST in 3-body Heisenberg example gives a more accurate answer,
however Quantum Belief Propagation (QBP) runs faster based on complexity. In
order to develop it in the future, we should be looking for ways to increase
the accuracy of QBP.
