Jernej Mravlje Home Page

  Jernej Mravlje,
  Department of Theoretical Physics,
  Institute Jozef Stefan, Jamova 39,
  SI-1001 Ljubljana, Slovenia.

  e-mail: jernej.mravlje@ijs.si
  phone: +386 1 477-3797
  room:   C-106a

Research   Teaching   Group seminars   Miscelaneous

I am a researcher working in theoretical solid state physics. I am interested in electronic correlations in mesoscopic and bulk systems. The term electronic correlations stands for effects of strong Coulomb interaction, that for instance characterizes transition-metal oxides, such as high-temperature superconductors, cuprates. Currently, most of my research is devoted to the problem of electronic correlations in a realistic multi-orbital setting. The material families I am working on are ruthenate, technetium, and nickelate perovskites. The research in this subject that bridges the theoretical physics and the material science proceeds via many quite different layers. It starts from the description of the crystal structure and the atomic physics of the material constituents but is ultimately interested in low-energy properties that are described within a field theory. In the large dimensionality limit, the bulk correlated problem translates to a self-consistent quantum impurity problem (DMFT, dynamical mean field theory). This enables numerical analysis of correlated material via the combination of ab initio density functional methods (DFT) with DMFT. I am interested also in the effects of electronic correlation on the meso(nano)-scale, as revealed in measurements of transport through nanostructures or by probing the magnetic ad-atoms on surfaces by a scanning tunneling microscope. List of publications (google scholar)


Research highlights

Bad-metallic transport


Resillient quasiparticles in a warm bad metal.
Many metals in which electronic correlations are important are bad , that is, resisistivity in them exceeds the Mott-Ioffe-Regel value which corresponds to the resistivity a material has when the scattering events are so frequent that the electron mean-free path is equivalent to the lattice spacing. In a paper we explored the temperature evolution of resistivity and the relation of resistivity to the spectral properties in a simple model DMFT setting. On the technical side, in this paper we found an excellent agreement between the real-frequency numerical renormalization group solver and the quantum Monte-Carlo hybridization expansion results.

Electronic correlations in multi-orbital materials


Strong correlations from Hund's coupling.
Published in Annual Review of Condensed Matter Physics
Many materials are multi-orbital, that is, more than one active orbital is important. The Hund's rule coupling that splits atomic multiplet splittings has been found to importantly affect the strength of electronic correlations in a way that depends on the filling of the orbitals. Hund's rule coupling can cause strong correlations far from a Mott insulating state. Materials in which Hund's rule coupling is playing the key role are known as Hund's metals. Ruthenates and iron pnictides are important members of that family of compounds.

More...

I am advising a PhD student Alen Horvat . We are working on problem of magnetism in Tc perovskites and on ab-initio simulations of thermoelectric materials.
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