Stefan Blügel

Prof. Dr. Stefan Blügel

Head of Institutes: Peter Grünberg Institute (PGI-1) and Institute for Advanced Simulation (IAS-1)

Professur for Theoretical Physics at RWTH Aachen University

Forschungsthemen

Theory of electronic properties of solids, quantum materials, topological properties, spin-orbit related phenomena, magnetism, spintronics, electronic structure methods, supercomputing

Kontakt

+49 2461/61-4249

+49 2461/61-2850

E-Mail

http://www.fz-juelich.de/pgi/Bluegel_S

Lecture Notes

Fleur Project

Art Gallery

Adresse

Forschungszentrum Jülich GmbH
Wilhelm-Johnen-Straße
52428 Jülich

Peter Grünberg Institut (PGI)

Quanten-Theorie der Materialien (PGI-1/IAS-1)

Gebäude 04.8 / Raum R 152

Warum und woran ich forsche

I belong to the first generation of Diploma and PhD students in Germany developing (see Ref [5] of Publication list for Wannier90, Zenodo (2023), DOI: 10.5281/zenodo.7576163 for FLEUR code) and applying density-functional theory (DFT) methods. I belong to an international team that tests methods [2] and applies these methods to scientific problems related to spintronics, magnetism and quantum materials. During my diploma studies, I developed the constraint DFT [7], during the PhD studies, after a research stint with Henry Krakauer at the College of William and Mary, I moved to the field of surface and thin-film magnetism. I predicted in 1988 [PRL 60, 1077 (1988)] the existence of antiferromagnetism in metallic magnetic monolayers, that was confirmed experimentally 12 years later [Science 288, 1805 (2000)]. Following a large number of fundamental contributions to computer-aided solid-state research, in particular to magnetism at surfaces and interfaces, I recognized that the relativistic spin-orbit coupling effects of electrons in solids in conjunction with breaking the inversion symmetry at inner and outer interfaces leads to the occurrence of large intrinsic magnetic fields at the interfaces. Essential results are: The large Rashba effect at interfaces [6] as a basis for new spin transport phenomena like the spin-orbit torque [3] and terahertz generation [9]; the interface-inducedDzyaloshinskii-Moriya interaction [1], which became the origin of the experimental discovery of homochiral spin structures at interfaces [7] or homochiral domain walls [8]. The latter have proved to be exceptionally useful in improving the performance of magnetic racetrack memory and are already actively used in this capacity. I realized that the particular mathematical form of the new magnetic interface interaction facilitates the formation of skyrmions. For that purpose, for example a skyrmion lattice at an interface could be proved experimentally for the first time [1]. I am pretty happy about our implementation of the spin excitations in solids from many-body perturbation theory [Top. Curr. Chem. 347, 359 (2014)] and the implementation of the electron-plasmon and the electron magnon interaction on the same footing combining the GW and the GT approximation on the same footing (njp Computational Materials 7, 178 (2021)). I am excited by the recent developments of the spectral density-functional theory [PRB 106, 045135 (2022), ibid 107, 005100 (2022)], the field of orbitronics [Phys. Rev. Research 2, 033401 (2020)], the potential provided by autonomous computing to scan the chemical phase space of materials and the development of cryo-spintronics combining spintronics with magnetic materials. I have a permanent interest to improve electronic structure methods in their performance and their functionality. I am currently working on Hopfions, on Weyl semimetals, magnetic materials hosting achiral skyrmions stabilized by RKKY interaction, 2D-materials, at covalent magnetism. One of my dreams is to develop RPA-type total energy approaches from our recently implemented GWT self-energy for magnetic materials, to study the spin-phonon interaction in 2D-materials, to treat longitudinal and transversal spin-fluctuation on the same footing, treating finite temperature magnetism with short-range order etc etc….

Vita
Publikationen
Letzte Änderung: 12.01.2024