16. Februar 2022
M. Alexander and M. Kollar
Photoinduced Prethermalization Phenomena in Correlated Metals
phys. stat. sol (b) 202100280

Prethermalization phenomena in weakly interacting Hubbard systems after electric-field pump pulses with a finite duration are studied. The Hubbard interaction U is taken into account up to second order, by applying the prethermalization paradigm for time-dependent interaction protocols, and the electric field strength beyond linear order. A scaling behavior with pulse duration is observed for the absorbed energy as well as individual prethermalized momentum occupation numbers, which are attributed to the leading quadratic orders in interaction and electric field. It is shown that a pronounced nonthermal momentum distribution can be created with pump pulses of suitable resonance frequencies, and how to distinguish them from thermal states is discussed.

8. Dezember 2020
S. Huber and M. Kollar
From Luttinger liquids to Luttinger droplets via higher-order bosonization identities
Phys. Rev. Research 2, 043336 (2020)

We derive generalized Kronig identities expressing quadratic fermionic terms including momentum transfer to bosonic operators and use them to obtain the exact solution for one-dimensional fermionic models with linear dispersion in the presence of position-dependent local interactions and scattering potential. In these Luttinger droplets, which correspond to Luttinger liquids with spatial variations or constraints, the position dependencies of the couplings break the translational invariance of correlation functions and modify the Luttinger-liquid interrelations between excitation velocities.