Multi-cluster wavefunctions with arbitrary permutational symmetry

N. Grama

A. Mushinski

Akiva Novoselsky, Jacob Katriel

The authors consider a system of identical particles distributed in two clusters and described by harmonic oscillator wavefunctions. A set of non-spurious two-cluster states, whose centre-of-mass is at rest, is constructed. It is characterized by the cluster Yamanouchi symbols as well as by its overall permutational symmetry, angular momentum and total energy. Applications to nuclear cluster models, to the evaluation of nuclear spectroscopic factors, to the description of nuclei as quark-clusters, and to the study of interacting rare-gas clusters are pointed out.

Walter Greiner, Ludwig Neise, Horst Stöcker B

Michael Gegg, Marten Richter

In a recent publication we showed that permutation symmetry reduces the numerical complexity of Lindblad quantum master equations for identical multi-level systems from exponential to polynomial scaling. This is important for open system dynamics including realistic system bath interactions and dephasing in, for instance, the Dicke model, multi-Λ system setups etc. Here we present an object-oriented C++ library that allows to setup and solve arbitrary quantum optical Lindblad master equations, especially those that are permutationally symmetric in the multi-level systems. PsiQuaSP (Permutation symmetry for identical Quantum Systems Package) uses the PETSc package for sparse linear algebra methods and differential equations as basis. The aim of PsiQuaSP is to provide flexible, storage efficient and scalable code while being as user friendly as possible. It is easily applied to many quantum optical or quantum information systems with more than one multi-level system. We first review the basics of the permutation symmetry for multi-level systems in quantum master equations. The application of PsiQuaSP to quantum dynamical problems is illustrated with several typical, simple examples of open quantum optical systems.

Alexander S. Ovchinnikov, Irina Gennad'evna Bostrem, Vl. E. Sinitsyn