Superconductivity and magnetism: two contrasting manifestations of electron correlations in light-element molecular solids

Speaker: Denis ARČON (University of Ljubljana)

Time: November 23, 2023 09:00

Place: 理科楼C302

报告摘要:Light element molecular solids with s/p-based outer electrons in which a fine balance exists between electron-phonon coupling and electron correlation energies can give rise to some most intriguing electronic properties usually associated only with the transition-metal ions. These systems are naturally narrow-band solids where on-site repulsion is comparable to or larger than the electronic bandwidth. Moreover, in cases when the degeneracy of the frontier molecular orbitals is preserved the interplay between the Hund's rule coupling and Jahn-Teller effect lead to a very rich phase diagram where correlated superconducting state borders the Mott-insulating antiferromagnetic phase [1,2].

In this talk we will report on our comprehensive studies of bandwidth-controlled antiferromagnetic Mott insulator-metal/superconductor transition in face-centred-cubic (f.c.c.) alkali-doped fullerides, A3C60 (A = alkali metal) [1-4]. The richness of these families stem from the simultaneous presence of orientational, charge, orbital, and spin degrees of freedom that are strongly coupled as also revealed from our comprehensive magnetic resonance studies.

[1] Y. Takabayashi, D. Arčon et al., Science 323, 1585 (2009).

[2] A. Y. Ganin, D. Arčon et al., Nature 466, 221 (2010).

[3] A. Potočnik et al., Sci. Rep. 4, 4265 (2014).

[4] R.H. Zadik et al. Sci. Adv. 1, e1500059 (2015).

报告人简介:Denis ARČON received his Bachelor of Science, Physics, Faculty of Mathematics and Physics, University of Ljubljana 1989-1993 and Doctor of Philosophy, Physics, Faculty of mathematics and physics, University of Ljubljana, Slovenia in 1997. He spent his Post-doctoral position at the University of Sussex, Brighton, UK from 1997-2000. He became Researcher at the Institute Jozef Stefan, Ljubljana in 2000, Slovenia, Assistant Professor at the Faculty of Mathematics and Physics, University of Ljubljana, Slovenia in 2001 and became the head of Pulsed EPR laboratory; Solid state physics department, Institute Jozef Stefan Institute. He became Professor of Josef Stefan Institute in 2009. He is presently the head of Department of Physics, Jozef Stephane Institute and also Professor at the Faculty of Mathematics and Physics, University of Ljubljana, Slovenia. He was awarded International Union for Materials Research (IUMRS) Award in 1999, Jožef Stefan Golden Emblem Prize in 2008, Žiga Zois Award in 2019 for his outstanding achievements in the fields of quantum magnetism and unusual superconductivity.