Five years of density matrix embedding theory
  Density matrix embedding theory (DMET) describes finite fragments in the presence of a surrounding environment. In contrast to most embedding methods, DMET explicitly allows for quantum entanglement between both. In this chapter, we discuss both the ground-state and response theory formulations of DMET, and review several applications. In addition, a proof is given that the local density of states can be obtained by working with a Fock space of bath orbitals. 
Sebastian Wouters, Carlos A. Jim\'enez-Hoyos and Garnet K.-L. Chan
cond-mat.str-el physics.chem-ph