https://doi.org/10.1140/epjb/e2014-50028-2
Regular Article
Linear response within the projector-based renormalization method: many-body corrections beyond the random phase approximation
1
Institute of Research and Development, Duy Tan
University, K7/25 Quang
Trung, Danang,
Vietnam
2
Institut für Physik, Ernst-Moritz-Arndt-Universität
Greifswald, 17489
Greifswald,
Germany
3
Institut für Theoretische Physik, Technische Universität
Dresden, 01062
Dresden,
Germany
a
e-mail: klaus.w.becker@tu-dresden.de
Received: 13 January 2014
Received in final form: 12 February 2014
Published online: 12 March 2014
The explicit evaluation of linear response coefficients for interacting many-particle systems still poses a considerable challenge to theoreticians. In this work we use a novel many-particle renormalization technique, the so-called projector-based renormalization method, to show how such coefficients can systematically be evaluated. To demonstrate the prospects and power of our approach we consider the dynamical wave-vector dependent spin susceptibility of the two-dimensional Hubbard model and also determine the subsequent magnetic phase diagram close to half-filling. We show that the superior treatment of (Coulomb) correlation and fluctuation effects within the projector-based renormalization method significantly improves the standard random phase approximation results.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2014