Coupled Cluster Method and Entanglement

Rövid cím: 
Coupled Cluster Method and Entanglement
2015. 10. 02. 10:15
BME Fizikai Intézet, Elméleti Fizika Tanszék, Budafoki út 8. F-épület, III lépcsőház, szemináriumi szoba
Péter Lévay

The Coupled Cluster (CC) and full CI expansions are studied for three fermions with six  and seven modes. Surprisingly, the CC expansion is tailor made to characterize the usual SLOCC (Stochastic Local Operations and Classical Communication) entanglement classes. It means that the notion of a SLOCC transformation shows up quite naturally as a one relating the CC and CI expansions, and going from the CI expansion to the CC one is equivalent to obtaining a canonical form for the state where the structure of the entanglement classes is transparent. In this picture entanglement is characterized by the parameters of the cluster operators describing transitions from occupied states to singles, doubles and triples of nonoccupied ones.