NanoStructures is a program used to determine various layer-resolved correlators (both layer-diagonal and intra-layer), local layer self-energies and certain in-plane conductivities in a strongly-correlated, layered nanostructure. The nanostructure is modelled here as a Hubbard model, where one or several of the parameters change as a function of one of the coordinates. The program iterates the dynamical mean field theory (DMFT) equations until convergence and then determines layer-resolved properties.

In DMFT the correlated lattice problem is mapped onto a set of self-consistenly determined (coupled) impurity problems - one for each layer. In this program the numerical renormalization group is used to solve these resulting impurity problems in each iteration of the DMFT.

References

Although the source code is documented and the documentation in the NRG and DMFT class try to eludicate some of the underlying physical ideas, it is advisable to consult the standard references for the NRG and DMFT before reading the source code.

Numerical Renormalization Group

• Bulla, Ralf, Theo A. Costi, and Thomas Pruschke. "Numerical renormalization group method for quantum impurity systems." Reviews of Modern Physics 80.2 (2008): 395.
• Krishna-Murthy, H. R., J. W. Wilkins, and K. G. Wilson. "Renormalization-group approach to the Anderson model of dilute magnetic alloys. I. Static properties for the symmetric case." Physical Review B 21.3 (1980): 1003.
• Krishna-Murthy, H. R., J. W. Wilkins, and K. G. Wilson. "Renormalization-group approach to the Anderson model of dilute magnetic alloys. II. Static properties for the asymmetric case." Physical Review B 21.3 (1980): 1044.

Dynamical Mean Field Theory

• Georges, A., Kotliar, G., Krauth, W., & Rozenberg, M. J. (1996). Dynamical mean-field theory of strongly correlated fermion systems and the limit of infinite dimensions. Reviews of Modern Physics, 68(1), 13.
• Kotliar, Gabriel, and Dieter Vollhardt. "Strongly correlated materials: Insights from dynamical mean-field theory." Physics Today 57.3 (2004): 53-60.
• Pavarini, Eva, et al. The LDA+ DMFT Approach to Strongly Correlated Materials–Lecture Notes of the Autumn School 2011 Hands-on LDA+ DMFT. 2011.