Exploring excited eigenstates of many-body systems using the functional renormalization group
C. Klöckner, Dante Marvin Kennes, Christoph Karrasch
We introduce approximate, functional renormalization group based schemes to obtain correlation functions in pure excited eigenstates of large fermionic many-body systems at arbitrary energies. The algorithms are thoroughly benchmarked and their strengths and shortcomings are documented using a one-dimensional interacting tight-binding chain as a prototypical testbed. We study two ``toy applications'' from the world of Luttinger liquid physics: the survival of power laws in lowly excited states as well as the spectral function of high-energy ``block'' excitations, which feature several single-particle Fermi edges.
arXiv:1711.01127•Physical review. B./Physical review. B•May 14, 2018•1 citation