Density matrix renormalization group approach for many-body open quantum   systems
  The density matrix renormalization group (DMRG) approach is extended to complex-symmetric density matrices characteristic of many-body open quantum systems. Within the continuum shell model, we investigate the interplay between many-body configuration interaction and coupling to open channels. It is shown that the DMRG technique applied to broad resonances in the unbound neutron-rich nucleus 7He provides a highly accurate treatment of the coupling to the non-resonant scattering continuum. 
J. Rotureau, N. Michel, W. Nazarewicz, M. Ploszajczak, and J. Dukelsky