Calculation of Quantum Entanglement

Quantum entanglement which is used as the basis for such applications as quantum cryptography, quantum teleportation, and quantum computing, is a multifaceted property that has attracted much attention. The calculation of quantum entanglement therefore has become important. But the calculation of entanglement has become much more complex as systems that use entanglement have evolved. Based on the relative entropy of entanglement, a general method was developed for the calculation of entanglement for n-qubit or n-qudit system, which using an optimization algorithm technique such as genetic algorithm or Quantum-behaved Particle Swarm Optimization. The method using different optimization algorithm was tested on a two qubit system, for which there are some known points, and compared to exact calculations using the entanglement of formation and with each other. Advantages and disadvantages of the method are discussed and directions of future research are exposed.