Exotic magnetism and electron-correlation phenomena at the surface and in the bulk of rare-earth based materials

• Applicants: Professor Dr. Cornelius Krellner; Professor Dr. Clemens Laubschat
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 348742864

• Final Report Year: 2023

Final Report Abstract

The project has addressed unusual magnetic properties as well as electron-correlation phenomena in lanthanide-based transition-metal compounds. Particular attention was paid to the crystal growth of high-quality materials which subsequently were deeply investigated by magnetic and spectroscopic techniques. Special attention was paid to surface properties in comparison to properties in the bulk of the system. Within this project several fascinating results have been found. Among them is a universal temperature scale for valence changes in Ybbased Kondo systems, the emergence of 2D ferromagnetism at the surface of otherwise nonmagnetic EuIr2Si2, the cubic Rashba effect in the surface spin structure of TbRh2Si2, and longlived spin waves in the terahertz regime in the metallic antiferromagnet CeCo2P2.

Publications

• Crystal electric field in CeRh2Si2 studied with high-resolution resonant inelastic soft x-ray scattering. Physical Review B, 97(24).
  Amorese, A.; Caroca-Canales, N.; Seiro, S.; Krellner, C.; Ghiringhelli, G.; Brookes, N. B.; Vyalikh, D. V.; Geibel, C. & Kummer, K.
  
• Crystal growth and magnetic characterization of HoIr2Si2 (I4/mmm). Journal of Physics: Condensed Matter, 30(38), 385801.
  Kliemt, K.; Bolte, M. & Krellner, C.
  
• Similar temperature scale for valence changes in Kondo lattices with different Kondo temperatures. Nature Communications, 9(1).
  Kummer, K.; Geibel, C.; Krellner, C.; Zwicknagl, G.; Laubschat, C.; Brookes, N. B. & Vyalikh, D. V.
  
• Strong spin-orbit coupling in the noncentrosymmetric Kondo lattice. Physical Review B, 98(11).
  Generalov, A.; Falke, J.; Nechaev, I. A.; Otrokov, M. M.; Güttler, M.; Chikina, A.; Kliemt, K.; Seiro, S.; Kummer, K.; Danzenbächer, S.; Usachov, D.; Kim, T. K.; Dudin, P.; Chulkov, E. V.; Laubschat, C.; Geibel, C.; Krellner, C. & Vyalikh, D. V.
  
• Weak magnetic anisotropy in GdRh2Si2 studied by magnetic resonance. Physical Review B, 97(21).
  Sichelschmidt, J.; Kliemt, K.; Hofmann-Kliemt, M. & Krellner, C.
  
• Bulk properties of single crystals of the valence-unstable compound SmRh2Si2. Materials Research Express, 6(12), 126104.
  Kliemt, K.; Banda, J.; Geibel, C.; Brando, M. & Krellner, C.
  
• Crystal Growth of Materials with the ThCr2Si2 Structure Type. Crystal Research and Technology, 55(2).
  Kliemt, Kristin; Peters, Marius; Feldmann, Fabian; Kraiker, Alexej; Tran, Doan‐My; Rongstock, Susanna; Hellwig, Johannes; Witt, Sebastian; Bolte, Michael & Krellner, Cornelius
  
• Divalent EuRh2Si2 as a reference for the Luttinger theorem and antiferromagnetism in trivalent heavy-fermion YbRh2Si2. Nature Communications, 10(1).
  Güttler, M.; Generalov, A.; Fujimori, S. I.; Kummer, K.; Chikina, A.; Seiro, S.; Danzenbächer, S.; Koroteev, Yu. M.; Chulkov, E. V.; Radovic, M.; Shi, M.; Plumb, N. C.; Laubschat, C.; Allen, J. W.; Krellner, C.; Geibel, C. & Vyalikh, D. V.
  
• Emerging 2D-ferromagnetism and strong spin-orbit coupling at the surface of valence-fluctuating EuIr2Si2. npj Quantum Materials, 4(1).
  Schulz, Susanne; Nechaev, Ilya A.; Güttler, Monika; Poelchen, Georg; Generalov, Alexander; Danzenbächer, Steffen; Chikina, Alla; Seiro, Silvia; Kliemt, Kristin; Vyazovskaya, Alexandra Yu.; Kim, Timur K.; Dudin, Pavel; Chulkov, Evgueni V.; Laubschat, Clemens; Krasovskii, Eugene E.; Geibel, Christoph; Krellner, Cornelius; Kummer, Kurt & Vyalikh, Denis V.
  
• Cubic Rashba Effect in the Surface Spin Structure of Rare-Earth Ternary Materials. Physical Review Letters, 124(23).
  Usachov, D. Yu.; Nechaev, I. A.; Poelchen, G.; Güttler, M.; Krasovskii, E. E.; Schulz, S.; Generalov, A.; Kliemt, K.; Kraiker, A.; Krellner, C.; Kummer, K.; Danzenbächer, S.; Laubschat, C.; Weber, A. P.; Sánchez-Barriga, J.; Chulkov, E. V.; Santander-Syro, A. F.; Imai, T.; Miyamoto, K.; ... & Vyalikh, D. V.
  
• Deterministic control of an antiferromagnetic spin arrangement using ultrafast optical excitation. Communications Physics, 3(1).
  Windsor, Y. W.; Ernst, A.; Kummer, K.; Kliemt, K.; Schüßler-Langeheine, Ch.; Pontius, N.; Staub, U.; Chulkov, E. V.; Krellner, C.; Vyalikh, D. V. & Rettig, L.
  
• Photoelectron diffraction for probing valency and magnetism of 4f-based materials: A view on valence-fluctuating EuIr2Si2. Physical Review B, 102(20).
  Usachov, D. Yu.; Tarasov, A. V.; Schulz, S.; Bokai, K. A.; Tupitsyn, I. I.; Poelchen, G.; Seiro, S.; Caroca-Canales, N.; Kliemt, K.; Mende, M.; Kummer, K.; Krellner, C.; Muntwiler, M.; Li, Hang; Laubschat, C.; Geibel, C.; Chulkov, E. V.; Fujimori, S. I. & Vyalikh, D. V.
  
• Spin structure of spin-orbit split surface states in a magnetic material revealed by spin-integrated photoemission. Physical Review B, 101(24).
  Usachov, D. Yu.; Güttler, M.; Schulz, S.; Poelchen, G.; Seiro, S.; Kliemt, K.; Kummer, K.; Krellner, C.; Laubschat, C.; Chulkov, E. V. & Vyalikh, D. V.
  
• Unexpected differences between surface and bulk spectroscopic and implied Kondo properties of heavy fermion CeRh2Si2. npj Quantum Materials, 5(1).
  Poelchen, Georg; Schulz, Susanne; Mende, Max; Güttler, Monika; Generalov, Alexander; Fedorov, Alexander V.; Caroca-Canales, Nubia; Geibel, Christoph; Kliemt, Kristin; Krellner, Cornelius; Danzenbächer, Steffen; Usachov, Dmitry Yu.; Dudin, Pavel; Antonov, Victor N.; Allen, James W.; Laubschat, Clemens; Kummer, Kurt; Kucherenko, Yuri & Vyalikh, Denis V.
  
• Classical and cubic Rashba effect in the presence of in-plane 4 f magnetism at the iridium silicide surface of the antiferromagnet GdIr2Si2. Physical Review B, 103(3).
  Schulz, S.; Vyazovskaya, A. Yu.; Poelchen, G.; Generalov, A.; Güttler, M.; Mende, M.; Danzenbächer, S.; Otrokov, M. M.; Balasubramanian, T.; Polley, C.; Chulkov, E. V.; Laubschat, C.; Peters, M.; Kliemt, K.; Krellner, C.; Usachov, D. Yu. & Vyalikh, D. V.
  
• Insight into the Temperature Evolution of Electronic Structure and Mechanism of Exchange Interaction in EuS. The Journal of Physical Chemistry Letters, 12(34), 8328-8334.
  Fedorov, A. V.; Poelchen, G.; Eremeev, S. V.; Schulz, S.; Generalov, A.; Polley, C.; Laubschat, C.; Kliemt, K.; Kaya, N.; Krellner, C.; Chulkov, E. V.; Kummer, K.; Usachov, D. Yu.; Ernst, A. & Vyalikh, D. V.
  
• Strong Rashba Effect and Different f−d Hybridization Phenomena at the Surface of the Heavy‐Fermion Superconductor CeIrIn5. Advanced Electronic Materials, 8(3).
  Mende, Max; Ali, Khadiza; Poelchen, Georg; Schulz, Susanne; Mandic, Vladislav; Tarasov, Artem V.; Polley, Craig; Generalov, Alexander; Fedorov, Alexander V.; Güttler, Monika; Laubschat, Clemens; Kliemt, Kristin; Koroteev, Yury M.; Chulkov, Evgueni V.; Kummer, Kurt; Krellner, Cornelius; Usachov, Dmitry Yu. & Vyalikh, Denis V.
  
• Visualizing the Kondo lattice crossover in YbRh2Si2 with Compton scattering. Physical Review B, 103(11).
  Güttler, M.; Kummer, K.; Kliemt, K.; Krellner, C.; Seiro, S.; Geibel, C.; Laubschat, C.; Kubo, Y.; Sakurai, Y.; Vyalikh, D. V. & Koizumi, A.
  
• Crystal electric field and properties of 4 f magnetic moments at the surface of the rare-earth compound TbRh2Si2. Physical Review B, 106(15).
  Tarasov, Artem V.; Glazkova, Daria; Schulz, Susanne; Poelchen, Georg; Kliemt, Kristin; Kraiker, Alexej; Muntwiler, Matthias; Laubschat, Clemens; Generalov, Alexander; Polley, Craig; Krellner, Cornelius; Vyalikh, Denis V. & Usachov, Dmitry Yu.
  
• Effect of symmetry reduction on the magnetic properties ofLnIr2Si2 polymorphs. Journal of Magnetism and Magnetic Materials, 552, 169199.
  Kliemt, K.; Reusch, J.D.; Bolte, M. & Krellner, C.
  
• Estimating the Orientation of 4f Magnetic Moments by Classical Photoemission. The Journal of Physical Chemistry Letters, 13(33), 7861-7869.
  Usachov, Dmitry Yu.; Glazkova, Daria; Tarasov, Artem V.; Schulz, Susanne; Poelchen, Georg; Bokai, Kirill A.; Vilkov, Oleg Yu.; Dudin, Pavel; Kummer, Kurt; Kliemt, Kristin; Krellner, Cornelius & Vyalikh, Denis V.
  
• Exchange scaling of ultrafast angular momentum transfer in 4f antiferromagnets. Nature Materials, 21(5), 514-517.
  Windsor, Y. W.; Lee, S.-E.; Zahn, D.; Borisov, V.; Thonig, D.; Kliemt, K.; Ernst, A.; Schüßler-Langeheine, C.; Pontius, N.; Staub, U.; Krellner, C.; Vyalikh, D. V.; Eriksson, O. & Rettig, L.
  
• Interlayer Coupling of a Two-Dimensional Kondo Lattice with a Ferromagnetic Surface in the Antiferromagnet CeCo2P2. ACS Nano, 16(3), 3573-3581.
  Poelchen, Georg; Rusinov, Igor P.; Schulz, Susanne; Güttler, Monika; Mende, Max; Generalov, Alexander; Usachov, Dmitry Yu.; Danzenbächer, Steffen; Hellwig, Johannes; Peters, Marius; Kliemt, Kristin; Kucherenko, Yuri; Antonov, Victor N.; Laubschat, Clemens; Chulkov, Evgueni V.; Ernst, Arthur; Kummer, Kurt; Krellner, Cornelius & Vyalikh, Denis V.
  
• Robust Magnetic Order Upon Ultrafast Excitation of an Antiferromagnet. Advanced Materials Interfaces, 9(36).
  Lee, Sang‐Eun; Windsor, Yoav William; Fedorov, Alexander; Kliemt, Kristin; Krellner, Cornelius; Schüßler‐Langeheine, Christian; Pontius, Niko; Wolf, Martin; Atxitia, Unai; Vyalikh, Denis V. & Rettig, Laurenz
  
• Structural instability at the In-terminated surface of the heavy-fermion superconductor CeIrIn5. Surfaces and Interfaces, 32, 102126.
  Tarasov, Artem V.; Mende, Max; Ali, Khadiza; Poelchen, Georg; Schulz, Susanne; Vilkov, Oleg Yu.; Bokai, Kirill A.; Muntwiler, Matthias; Mandic, Vladislav; Laubschat, Clemens; Kliemt, Kristin; Krellner, Cornelius; Vyalikh, Denis V. & Usachov, Dmitry Yu.
  
• Insight into the Temperature-Dependent Canting of 4f Magnetic Moments from 4f Photoemission. The Journal of Physical Chemistry Letters, 14(24), 5537-5545.
  Usachov, D. Yu.; Tarasov, A. V.; Glazkova, D.; Mende, M.; Schulz, S.; Poelchen, G.; Fedorov, A. V.; Vilkov, O. Yu.; Bokai, K. A.; Stolyarov, V. S.; Kliemt, K.; Krellner, C. & Vyalikh, D. V.
  
• Long-lived spin waves in a metallic antiferromagnet. Nature Communications, 14(1).
  Poelchen, G.; Hellwig, J.; Peters, M.; Usachov, D. Yu.; Kliemt, K.; Laubschat, C.; Echenique, P. M.; Chulkov, E. V.; Krellner, C.; Parkin, S. S. P.; Vyalikh, D. V.; Ernst, A. & Kummer, K.
  
• Microscopic analysis of the valence transition in tetragonal EuPd2Si2. Physical Review B, 107(7).
  Song, Young-Joon; Schulz, Susanne; Kliemt, Kristin; Krellner, Cornelius & Valentí, Roser