8 papers
Fermion condensation in a generalized Hatsugai-Kohmoto model with momentum-mixing Landau interactions
Jan Heinrich, Andreas Rückriegel, Peter Kopietz
The Hatsugai-Kohmoto (HK) model is an exactly solvable electronic lattice model where the interaction between electrons with opposite spin is diagonal in momentum space. We general…
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…
Bad metal behavior and Lifshitz transition of a Nagaoka ferromagnet
Jonas Arnold, Peter Kopietz, Andreas Rückriegel
Using an extension of the fermionic functional renormalization group for systems where strong correlations give rise to projected Hilbert spaces we calculate the phase diagram and…
Spontaneous magnon decay in two-dimensional altermagnets
Niklas Cichutek, Peter Kopietz, Andreas Rückriegel
We show that magnons in two-dimensional altermagnets can spontaneously decay at zero temperature. The decay rate is determined by quantum fluctuations and scattering processes invo…
Quantum fluctuations in two-dimensional altermagnets
Niklas Cichutek, Peter Kopietz, Andreas Rückriegel
The magnetic properties of two-dimensional altermagnets can be obtained from a square lattice Heisenberg model with antiferromagetic nearest neighbor interaction and two types of n…
Functional renormalization group approach to phonon modified criticality: anomalous dimension of strain and non-analytic corrections to Hooke's law
Max O. Hansen, Julia von Rothkirch, Peter Kopietz
We study the interplay between critical isotropic elasticity and classical Ising criticality using a functional renormalization group (FRG) approach which is implemented such that…