超導國家重點實驗室超導基礎理論和實驗技術系列講座（六十七）

報告題目： Heavy fermions: Interplay between Kondo entanglement, quantum criticality and unconventional superconductivity 報告人： Professor Frank Steglich, MPI for Chemical Physics of Solids, 01187 Dresden, Germany 報告時間： 2017年9月21日（星期四）下午2:00—4:00 報告地點：物理所M234報告廳聯系人：李世亮/ 8264-9351 摘要： Rare-earth- and actinide-based Kondo-lattice systems show strongly renormalized charge carriers with effective masses m* which are two to three orders of magnitude larger than the electron mass. Multiple low-temperature properties are observed for these materials, notably antiferromagnetic order below a Néel temperature TN, a “heavy” Fermi liquid phase, non-Fermi liquid behavior and/or unconventional superconductivity near an antiferromagnetic quantum critical point (QCP). At the latter, TN disappears in a smooth way under variation of a suited non-thermal control parameter, e.g., pressure and magnetic field [1, 2]. In this lecture, I will first address the Kondo effect, followed by a discussion of the relationship between superconductivity and magnetism. Then, heavy fermions and heavy-fermion superconductivity will be introduced, preceding a brief sketch of the so far established scenarios for antiferromagnetic QCPs, which refer to the conventional spin-density-wave QCP and the unconventional Kondo-destroying QCP, respectively. The isostructural tetragonal intermetallic compounds CeCu2Si2 and YbRh2Si2 turn out to be exemplary materials for these different QCP scenarios. Finally, we will focus on the interplay between quantum criticality and heavy-fermion superconductivity in the afore-mentioned two prototypical Kondo-lattice systems [3, 4].
References:
[1] F. Steglich and S. Wirth, Rep. Prog. Phys. 79, 084502 (2016).
[2] S. Wirth and F. Steglich, Nat. Rev. Mater. 1, 16051 (2016).
[3] O. Stockert et al., Nat. Phys. 7, 119 (2011).
[4] E. Schuberth et al., Science 351, 485 (2016). 報告人簡介： Frank Steglich received a Dr. rer. nat. from the University of Göttingen (Germany) and was a Professor of Physics at the Technical University of Darmstadt (Germany) for about twenty years. In 1996, he became the Founding Director of the Max Planck Institute for Chemical Physics of Solids, Dresden (Germany). Since 2012, he has been a Qiushi Distinguished Visiting Professor and Director of the Center for Correlated Matter at Zhejiang University, Hangzhou and Distinguished Visiting Professor at the Institute of Physics, Chinese Academy of Sciences, Beijing. From 2001 to 2007 he served as Vice President of the German Research Foundation (DFG). He currently is a member of the Scientific Committee of the Einstein Foundation, Berlin (Germany) and Chairman of the Scientific Advisory Board of the Center for “Electronic Correlations and Magnetism” at the University of Augsburg (Germany). His main research is devoted to materials containing strongly correlated electron systems and emerging phenomena such as unconventional superconductivity and quantum criticality. Previous awards include the DFG Gottfried Wilhelm Leibniz Prize, the Hewlett Packard Europhysics Prize, the Humboldt Gay Lussac Prize, the APS International Prize for New Materials, the IUPAP Magnetism Award, the DPG Stern Gerlach Medal and the Bernd T. Matthias Prize for Superconducting Materials. In 2005, Professor Frank Steglich received the “Order of Merit (“Grosses Bundesverdienstkreuz”) by the President of the Federal Republic of Germany. He has authored/co-authored more than 870 scientific articles in refereed journals.

超導國家重點實驗室 超導基礎理論和實驗技術系列講座（六十七）

超導國家重點實驗室超導基礎理論和實驗技術系列講座（六十七）