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Join us for a Department of Physics colloquium entitled “Correlation-driven topological semimetals” with Professor Silke Bühler-Paschen, Vienna University of Technology (TU Wien)

Please note – The lecture will run from 16:00-17:00, followed by refreshments from 17:00-18:00 in the Level 8 Common Room of the Blackett Building.

Biography

Silke Paschen is an experimental condensed matter physicist, with a research focus on strongly correlated electron systems. After her graduation at the Graz University of Technology, her PhD at EPFL Lausanne and research stays at ETH Zurich, the Max Planck Institute for Chemical Solid State Physics in Dresden and Nagoya University, she was appointed full professor of physics at the Vienna University of Technology (TU Wien). Since 2017, she has held a dual appointment with Rice University. She is an APS Fellow, Corresponding Member of the Austrian Academy of Sciences, and recipient of two ERC Advanced Grants. Her research ranges from materials synthesis to advanced physical property measurements under multiple extreme conditions, and includes also experiments at large facilities and intense collaboration with theory groups. Her current topics of interest are quantum criticality, strange metal behavior, and correlation-driven topological phases, with focus on heavy fermion compounds and related quantum materials.

Abstract

Electrons in solids are often described as independent particles, but in many materials their mutual interactions fundamentally reshape their behavior, giving rise to unexpected electronic states. When such strongly correlated states meet the concept of topology – which provides a new way of characterizing electronic states and their properties – entirely new forms of quantum matter can emerge.

Heavy fermion compounds provide a particularly promising setting for exploring this physics. In this colloquium, I will introduce Weyl-Kondo semimetals, a materials class in which strong electronic correlations drive the formation of Weyl nodes near the Fermi level [1-3]. I will present the remarkable signatures of topology found in Ce₃Bi₄Pd₃ [1,3], discuss the emerging theoretical understanding of these observations [4], and show how the topological properties can be tuned by magnetic fields [5].

Going beyond these first examples, I will discuss how symmetry considerations can guide the search for new correlation-driven topological phases [6]. Finally, I will present the discovery of a fundametally new topological phase emerging from a strange metal state – which lacks well-defined quasiparticles [7], and explore the prospects of this route to topology as a broader design principle for topological matter, extending well beyond heavy fermion systems [8].  

[1] S. Dzsaber et al., Phys. Rev. Lett. 118, 246601 (2017).

[2] H.-H. Lai et al., PNAS 115, 93 (2018).

[3] S. Dzsaber et al., PNAS 118, e2013386118 (2021).

[4] J. Dobilas et al., Phys. Rev. B 113, 085140 (2026); S. Sur et al., Phys. Rev. Lett. (accepted 2 October, 2026); L. Geng et al., Phys. Rev. Lett. (accepted 14 October, 2026).

[5] S. Dzsaber et al., Nat. Commun. 13, 5729 (2022).

[6] L. Chen et al., Nat. Phys. 18, 1341 (2022); K.-S. Lin et al., arXiv:2026.22185 (2026).

[7] D. M. Kirschbaum et al., Nat. Phys. 22, 218 (2026).

[8] G. Checkelsky et al., Nat. Rev. Mater. 9, 509 (2024).