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Gustav Bihlmayer: Dzyaloshinskii-Moriya Interaction

Dzyaloshinskii-Moriya Interaction [1,2]

  • Introduction, weak ferromagnetism
  • Relativistic exchange interactions basic symmetry considerations
  • Calculational methods:
    •  vector spin-density functional theory,
    •  spin-spiral calculations,
    •  Green's function methods
  • Examples:
    •  magnetic domain walls, skyrmions,
    •  magneto-electric coupling
  • Summary & outlook

[1] I. E. Dzialoshinskii, Sov. Phys. JETP 5, 1259 (1957) [2] T. Moriya, Phys. Rev. 120, 91 (1960)

Stephen Blundell: Experimental overview

Experimental techniques:  

  • Magnetic susceptibility,
  • Magnetisation,
  • Heat capacity,
  • NMR,
  • MuSR,
  • Neutron diffraction,
  • Inelastic neutron scattering

Examples of experimental systems:

  • Organic magnets
  • Single molecule magnets
  • Magnetism in competition with superconductivity
  • Low-dimensional magnets
  • Spin liquids
  • Spin ice

Luca de' Medici: Magnetism in Dynamical Mean Field Theory (DMFT)

  • Dynamical Mean-Field Theory
  • Instabilities and broken-symmetry phases in DMFT
  • Magnetism in the Hubbard model
  • Static vs dynamical mean-field
  • DFT+DMFT, some examples on materials

George Jackeli: Spin-Orbit Mott Insulators: Magnetism, Order, and Excitations

  • Introduction
    •  Mott insulator, Orbital degeneracy
    •  Spin-orbital exchange interactions
  • Spin-orbit coupling
    •   Angular momentum, local electronic structure, g-factors
    •  Exchange interactions in j-basis
  • Experimental implications
    •  j=1/2 systems: Iridates and Ruthenates
    •  j=3/2 systems: Vanadates, Molybdates,and Osmates

Erik Koch: Exchange Mechanisms

  • Coulomb exchange & Hund’s rules
  • Direct exchange
  • Superexchange & Goodenough/Kanamori rules
  • Double exchange
  • Orbital exchange & orbital ordering

More details can be found in these lecture notes.

    Juergen Kuebler: Overview and special topics in magnetism (theory)

    • Overview
      • Theory of magnetism: all problems solved? The most important temperature effects. Heisenberg versus Moriya. Fluctuations.
      • Trends in the Curie temperatures of Heusler compounds and applications in spintronics.
      • Antiferromagnets. Non-collinearity.
    • Special topics:
      • Topology in magnetism - the Berry phase.
      • The anomalous Hall effect (AHE), perhaps also the  spin Hall effect.
      • The AHE in antiferromagnets.

      Igor Mazin: Density functional theory of magnetism: learn from successes and learn from failures

      • Stoner I as the DFT counterpart of Hubbard U (the spin-part therof) and Heisenberg J together. LDA+U and effective I in LDA+U.
      • Andersen's extended Stoner theory for ferromagnetism in DFT. Application examples.
      • Two sources of errors in DFT (w.r.t. magnetism): Hubbard U (examples) and Moria's zero-point fluctuations (examples). Applications and implementations of Moria's theory. "Poor man's Moria", a.k.a. renormalized Stoner theory.
      • Basic magnetic interaction from the DFT point of view: (i) direct exchange (ii) superexchange (iii) FM superexchange (iv) FM direct (kinetic) exchange (v) double exchange (vi) RKKY
      • An example of applications of (4): theory of dilute magnetic superconductors (Ba,K)(Zn,Mn)2As2.

        Silvia Picozzi: Multiferroics

        • Basic ingredients
          • Ferroelectricity
          • Complex oxides
          • Symmetry Properties
          • Spin orbit coupling and Rashba effects
        • Multiferroics
          • Different classifications (proper vs improper, bulk vs composite, etc)
          • Electronic ferroelectricity (spin, charge, orbital)
          • Different classes: oxides, organics and organic-inorganic hybrids
        • Ferroelectric Rashba Semiconductors
          • Interplay between Rashba effect and ferroelectricity
          • Examples: GeTe, oxides, hyperferroelectrics
        •  Summary

        Antonio Sanna: Magnetism in Density Fuctional Theory for Superconductors

        Basics of ab-initio superconductivity in the density functional way:  SC-DFT

        • Functional construction and the effect of magnetism
        • Pairing with spin fluctuations: Derivation of a Spin fluctuation effective electron-electron interaction from the magnetic susceptibility and the exchange-correlation kernel of TD-DFT.
        • Its inclusion in SC-DFT
        • Gap symmetry and renormalization in presence of overlapping pairing channels:
        • phonons, spin fluctuations, plasmons ...

        Stefano Sanvito: Spintronics

        • Foundation of electron transport theory (non-equilibrium Green’s functions)
        • Electron transport in magnetic system and heterostructures (the tunnelling problem)
        • Giant magneto-resistance, tunnel magneto-resistance, spin-filtering at an interface
        • Spin-transfer torque from DFT and non-equilibrium Green’s function methods
        • Multi-scale approach to current-driven spin dynamics in heterostructures
        • Overview of organic spintronics (spin-relaxation in organic materials, concept of spinterface)


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        Lastupdate: 13.02.2017 - 16:55