Agenda

Quantum matter at non-integer dimension: topology and interactions

Cristiane Morais Smith (Institute for Theoretical Physics, Utrecht University, the Netherlands)

Date/Horaire : le jeudi 4 décembre 2025 à 11h00

Lieu : Salle Rémy Lemaire K223, Institut Néel

Résumé : We know how electrons behave in 1,2,3 dimensions, but what about d=1.58? In this talk, I will first describe fractals, structures that may have a non-integer dimension. I will present experiments on electronic 1, photonic 2, and cold atoms 3 quantum simulators and explain how electrons, photons, and Rydberg atoms with long-range interactions behave at fractal dimension. Then, I will discuss the topological properties of electrons in spontaneously formed fractals of single-layer bismuth on InSb 4. Finally, I will show that fractality itself can induce topological behavior, without the need of a magnetic field, spin-orbit coupling or dimerization 5. 1 S.N. Kempkes, M.R. Slot, S.E. Freeney, S.J.M. Zevenhuizen, D. Vanmaekelbergh, I. Swart, and C. Morais Smith, “Design and characterization of electronic fractals”, Nature Physics 15, 127 (2019) see also 15 years of Nature Physics, Nature Physics 16, 999 (2020). 2 X.-Y. Xu, X.-W. Wang, D.-Y. Chen, C. Morais Smith, and X.-M. Jin, “Quantum transport in fractal networks,” Nature Photonics 15, 703 (2021). 3 R.C. Verstraten, I.H.A. Knottnerus, Y.C. Tseng, A. Urech, T.S.E. Santo, V. Zampronio, F. Schreck, R.J.C. Spreeuw, and C. Morais Smith, “Control of single spin-flips in a Rydberg atomic fractal”, arXiv:2509.03514. 4 R. Canyellas , C. Liu, R. Arouca, L. Eek, Guanyong Wang, Yin Yin, Dandan Guan, Yaoyi Li, Shiyong Wang, Hao Zheng, Canhua Liu, Jinfeng Jia, and C. Morais Smith “Topological edge and corner states in Bi fractals on InSb,” Nature Physics 20, 1421 (2024). 5 L. Eek, Z. Osseweijer, and C. Morais Smith, “Fractality-induced Topology”, Phys. Rev. Lett. 134, 246601 (2025).