Jernej Mravlje Home Page

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

  phone: +386 1 477-3797
  room:   C-196

Research   Teaching   Jobs   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)

PhD position on the subject of transport in correlated materials. Write me!

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 highlights ...

Part of condensed matter program group P1-0044.
ARRS project J1-2458: Three advances towards realistic description of strongly correlated electron transport

Postdoc collaborators
Past postdocs:
Banhi Chatterjee Jointly with Denis Golez and Banhi we have been working on effects of excitonic condensation on optical conductivity. With Banhi we have also investigated jointly with the group of Tomaz Mertelj the changchengite compound (IrBiS). (2020-)
German Blesio With German we have been calculating the electronic Raman response within DFT+DMFT method. We have also been investigating transport properties of iron under inner and outer Earth core conditions. (2020-)
Luis Cort With Luis we have been investigating the transmission of a Josephson qubit coupled to cavity. (2020-2022)

Work with PhD students -- Write me if interested in Masters' or PhD work.
Luka Medic . We are working with Luka (supervised by Anton Ramsak and Tomaz Rejec) on high-harmonic generation in models for Weyl metals.

Past PhD students:
Alen Horvat . With Alen we worked on the problem of magnetism in Tc perovskites and on numerical renormalization group approaches to Hund's impurity systems and application to Hund's metals. Defended thesis in 2019.
Lara Ulcakar . Jointly with Tomaz Rejec and Anton Ramsak we worked on time-dependent topological band-structure problems. Defended thesis in 2020.
Martin Ulaga Martin has been calculating transport effects in 2d Hubbard model using FTLM and DMFT methods. He is interested in thermal transport and the effects of thermoelectric effects on diffusion. We supervised Martin Ulaga jointly with Jure Kokalj. Defended thesis in 2024.

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