nrgplusplus#
The numerical renormalization group (NRG) method is a powerful technique for investigating the low-energy properties of strongly correlated electronic systems. It has found widespread applications in condensed matter physics, including the study of quantum impurity models and the Kondo effect. In order to facilitate the implementation of the NRG method, several software packages have been developed, each with its own strengths and limitations.
nrgplusplus is implementation of the NRG method is written in the Modern C++ programming language. This package provides a versatile and efficient framework for performing NRG calculations. The C++ language is well-suited to numerical calculations, and the package has been designed with efficiency and speed in mind.
nrgcore takes two class as a template argument
for the Impurity model and the bath model. The bath model
is a class that describes bath. The impurity model is a class
that describes the impurity. In some cases the impurity class
model is also include the first Wilson site.
Each Model (bath or impurity) class should have these member vairables:
std::vector<qOperator> f_dag_operator
std::vector<std::vector<double>> eigenvalues_Q
std::vector<double> chi_Q
std::vector<std::vector<int>> n_Q