Project Details
Projekt
Spin and spin current dynamics in low-dimensional quantum magnets, manipulation of spin and current-carrying states in quantum dots
Subject Area
Theoretical Condensed Matter Physics
Term
from 2008 to 2015
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 39338622
Low-dimensional correlated electronic systems allow for novel spin dynamics and transport phenomena. In this project we use numerical as well as analytical tools, namely time-dependent density matrix renormalization group, quantum Monte-Carlo, exact diagonalization, and perturbation theory, to analyze spin transport and dynamics in model systems ranging from fully localized one-dimensional quantum magnets to correlated quantum dots. In the former, purely magnetic transport without carrier dynamics can be realized, while finite Coulomb correlations allow for a controlled crossover to the limit of localized electrons in the latter. Considering both, equilibrium as well as out-of-equilibrium situations, we will study time- and real-space as well as momentum- and frequency-resolved spin and spin current dynamics. We will extract characteristic time scales for coherence and relaxation and study their dependence on various control parameters. These control parameters include intrinsic model properties such as exchange topology, ground-state entanglement, Coulomb correlations, and dimensionality. Moreover, the impact of external parameters such as temperature, magnetic fields, bias, and initial states will be investigated. Finally, scattering off impurities and phonons will be studied. This research also aims at a better understanding of the large spin-heat transport observed in several low-dimensional transition metal compounds as well as the spin dynamics in double quantum dots, which are, for instance, realized in graphene and carbon nano-tubes.
DFG Programme
Research Units
