SKM 2023 – scientific programme

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MA: Fachverband Magnetismus

MA 40: Poster Magnetism II

MA 40.13: Poster

Thursday, March 30, 2023, 14:00–16:00, P2/EG

Anomalous relaxation dynamics of different types of impurity models — •Michael Elbracht and Michael Potthoff — I. Institute of Theoretical Physics, University of Hamburg, Germany

The real-time relaxation dynamics of different types of one-dimensional lattice models with two additional impurities is investigated numerically. We study purely classical, purely quantum mechanical as well as semiclassical systems: (i) a model with two classical spins exchanged coupled to the classical Heisenberg model, (ii) two classical spins exchanged coupled to a tight-binding model of independent electrons, and (iii) a model with the spins replaced by two additional orbitals locally hybridizing with the tight-binding chain.

After an initial local excitation of the impurities, we trace the real-time dynamics by solving the respective fundamental equations of motion. Depending on the exact position of the impurities, the system does or does not fully relax to its local ground state. In all cases, one observes for an even distance between the impurities and after a prerelaxation to a low-energy state, that the system is trapped in a stationary oscillatory mode. Various mechanisms for this incomplete relaxation are considered, including the dynamical emergence of conserved local quantities.