The density matrix embedding theory (DMET) is a numerical technique to solve strongly correlated electronic structure problems. By mapping the system to a fragment plus its entangled quantum bath, the local electron correlation effects on the fragment can be accurately modeled by a post-Hartree–Fock solver. This method has shown high-quality results in 1D- and 2D-

Hubbard model The Hubbard model is an approximate model used to describe the transition between conducting and insulating systems. It is particularly useful in solid-state physics. The model is named for John Hubbard. The Hubbard model states that each el ...

s,Density Matrix Embedding Theory (DMET)archived
from Princeton.edu, retrieved on 2015-09-07. and in chemical model systems incorporating the fully interacting electronic Hamiltonian, including long-range interactions. The basis of DMET is the Schmidt decomposition for quantum states, which shows that a given quantum many-body state, with macroscopically many degrees of freedom, K, can be represented exactly by an Impurity model consisting of 2N degrees of freedom for N<Density matrix of the impurity model and effective lattice model projected onto the impurity cluster match. When this matching is determined self-consistently, U thus derived in principle exactly models the correlations of the system (since the mapping from the full Hamiltonian to the impurity Hamiltonian is exact).

References

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