TY - JOUR
TI - Transport and magnetic properties of correlated electron systems
DO - https://doi.org/doi:10.7282/T3833TN6
PY - 2014
AB - This thesis investigates the transport and magnetic properties of correlated electron systems in the framework of dynamical mean field theory. In Chapter 2, the bad metallic transport in a doped Mott insulator is described by the Boltzmann theory of a hidden Fermi liquid, in which the quasiparticle scattering rate follows quadratic temperature and energy dependence far beyond the canonical Fermi liquid scale TFL. The quasiparticle renormalization is strongly dependent on temperature and energy, giving rise to the non-Fermi liquid transport, such as linear-in-T resistivity. Chapter 3 focuses on the thermoelectric power of correlated metals. The thermoelectric power in the high-frequency limit S* and in the Kelvin formula SK are compared with the transport limit S0. S* and SK can be computed with much less effort than S0. SK captures the contribution from renormalized density of states and is a better approximation of S0 for a strongly correlated metal, while for a weakly correlated metal, when S0 is dominated by the band velocity contribution, S* is a better indicator of S0. In Chapter 4, the phase diagram of a periodic Anderson model with the hybridization strength V as the tuning parameter is studied. The vanishing of the heavy Fermi liquid phase, characterized by a diminishing Fermi liquid scale TFL, is accompanied by the emergence of antiferromagnetic ordering. The dynamic spin susceptibility in the vicinity of magnetic instability indicates a momentum-independent, or localized picture of critical spin fluctuations. Chapter 5 discusses the the colossal Nernst effect and anomalies of the magnetoresistance in correlated semiconductor FeSb2. A phenomenological analysis based on Boltzmann theory suggests that a highly dispersive quasiparticle relaxation time is the key to understand the anomalous transport in FeSb2.
KW - Physics and Astronomy
KW - Mean field theory
KW - Fermi liquids
KW - Thermoelectricity
LA - eng
ER -