5 papers
Functional renormalization group for extremely correlated electrons
Jonas Arnold, Peter Kopietz, Andreas Rückriegel
At strong on-site repulsion , the fermionic Hubbard model realizes an extremely correlated electron system. In this regime, it is natural to derive the low-energy physics with…
Plasmon-sound hybridization in ionic crystals
Jakob Rappolt, Andreas Rückriegel, Peter Kopietz
We study the hybridization between plasmons, phonons, and electronic sound in ionic crystals using the Debye model, where the ionic background is modeled as a homogeneous, isotropi…
Recursive algorithm for generating high-temperature expansions for spin systems and the chiral non-linear susceptibility
Andreas Rückriegel, Dmytro Tarasevych, Jan Krieg +1
We show that the high-temperature expansion of the free energy and arbitrary imaginary-time-ordered connected correlation functions of quantum spin systems can be recursively obtai…
Phase diagram of the - quantum Heisenberg model for arbitrary spin
Andreas Rückriegel, Dmytro Tarasevych, Peter Kopietz
We use the spin functional renormalization group to investigate the - quantum Heisenberg model on a square lattice. By incorporating sum rules associated with the fixed l…
Non-Fermi liquid fixed point of the dissipative Yukawa-Sachdev-Ye-Kitaev model
Niklas Cichutek, Andreas Rückriegel, Peter Kopietz
Using a functional renormalization group approach we derive the renormalization group (RG) flow of a dissipative variant of the Yukawa-Sachdev-Ye-Kitaev model describing fermio…