Dr. Florian Eich

  • visitor funded by the German Research Foundation [DFG]: January 2015 – September 2015
  • post doctoral reseracher: September 2012 – December 2014

Research Group 2012

Quite generally my research orbits around developing density-functional theories. As part of my PhD thesis, written under the supervision of Hardy Gross, I have developed an approximation for the exchange-correlation energy for systems exhibiting non-collinear magnetism. This approximation uses the uniform electron gas in the so-called spin-spiral state as a reference system and thereby generalized the usual local density approximation to incorporate the effects of a non-trivial spin magnetization. Together with Stefano Pittalis and Giovanni Vignale I have furthermore investigated the gradient expansion of the exchange-correlation energy in spin-density-functional theory for non-collinear magnetism.

Recently my research focuses on introducing thermoelectric phenomena in a density-functional theory framework. In collaboration with Giovanni Vignale and Max Di Ventra, I have proposed an extension of the usual time-dependent density-functional theory dubbed thermal density-functional theory. The aim of thermal density-functional theory is to describe thermoelectric phenomena, the combined dynamics of charge and heat, in microscopic system from first principles. At present our theory is most suited to address inhomogeneous systems in the hydrodynamic regime, i.e., the regime where electron-electron collisions dominate over scattering with impurities and/or phonons. In a recent publication I have shown, together with Alessandro Principi, Giovanni Vignale and Max Di Ventra, that the description of thermoelectric transport a la Luttinger includes the standard description employing the Landauer-Buettiker or Meir-Wingreen formalism, but furthermore allows for a dynamical description of temperature variations. Moreover, we are currently investigating how a local temperature can be defined.

Selected Publications