Silke Buehler-Paschen1
Vienna University of Technology1
Silke Buehler-Paschen1
Vienna University of Technology1
The insight that nontrivial topology can be implemented in electronic materials via special configurations of their electronic bands has revolutionized condensed matter science. The broad bands of weakly interacting materials and their good description with density functional theory have been instrumental to visualize topological bandstructures (by ARPES). To uniquely identify low-energy topological signatures in transport or thermodynamic properties or even control them – the ultimate goal for topological quantum devices – has, however, remained challenging. This is where strongly correlated electron systems come into play. As evidenced for the noncentrosymmetric and nonsymmorphic heavy fermion material Ce<sub>3</sub>Bi<sub>4</sub>Pd<sub>3</sub> [1], strong electron correlations can drive ``extreme topological responses’’ [2-4]. Furthermore, the excellent tunability of strongly correlated electron systems in terms of their correlation physics [5] also allows to control the topological characteristic of these systems [6]. This paves the way for systematic studies of topological semimetals, which are much needed to reveal the stabilization mechanisms and discover new phases and phenomena.<br/><br/>[1] S. Dzsaber, L. Prochaska, A. Sidorenko, G. Eguchi, R. Svagera, M. Waas, A. Prokofiev, Q. Si, and S. Paschen, Kondo insulator to semimetal transformation tuned by spin-orbit coupling, Phys. Rev. Lett. <b>118</b>, 246601 (2017).<br/>[2] H.-H. Lai, S.E. Grefe, S. Paschen, and Q. Si, Weyl–Kondo semimetal in heavy-fermion systems, PNAS <b>115</b>, 93 (2018).<br/>[3] S. Dzsaber, X. Yan, M. Taupin, G. Eguchi, A. Prokofiev, T. Shiroka, P. Blaha, O. Rubel, S.E. Grefe, H.-H. Lai, Q. Si, and S. Paschen, Giant spontaneous Hall effect in a nonmagnetic Weyl-Kondo semimetal, PNAS <b>118</b>, e2013386118 (2021).<br/>[4] S.E. Grefe, H.-H. Lai, S. Paschen, and Q. Si, Weyl-Kondo semimetals in nonsymmorphic systems, Phys. Rev. B <b>101</b>, 075138 (2020).<br/>[5] S. Paschen and Q. Si, Quantum phases driven by strong correlations, Nat. Rev. Phys. <b>3</b>, 9 (2021).<br/>[6] S. Dzsaber, D.A. Zocco, A. McCollam, F. Weickert, R. McDonald, M. Taupin, X. Yan, A. Prokofiev, L.M.K. Tang, B. Vlaar, L. E. Winter, M. Jaime, Q. Si, and S. Paschen, Controlling correlation-driven electronic topology, arXiv:1906.01182.