3 papers
cond-mat.str-el2026
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…
cond-mat.str-el2025
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…
cond-mat.str-el2025
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…