Higher-dimensional topology in multi-terminal superconducting structures
Keywords: quantum science, superconductors, Andreev states, topology, synthetic dimensions
Topology ultimately unveils the roots of the perfect quantization observed in complex systems.The 2D quantum Hall effect is the celebrated archetype. Remarkably, topology can manifest itself even in higher-dimensional spaces defined by control parameters playing the role of synthetic dimensions. However, so far, a very limited number of implementations of higherdimensional topological systems have been proposed, a notable example being the so-called 4D quantum Hall effect. In this talk show how to engineer non-trivial topological signatures like Weyl-nodes in synthetic dimensions created by multi-terminal superconductors and how Berry spectroscopy can be used to extract information about the systems quantum geometry [1].
Furthermore, I will show that mesoscopic superconducting systems can implement higher dimensional
topology and represent a formidable platform to study a quantum system with a purely nontrivial second Chern number [2]. I discuss that these systems also admit a non-Abelian Berry phase. Hence, they also realize an enlightening paradigm of topological non-Abelian systems in higher dimensions. Furthermore, such systems can host exotic topological signatures like tensor monopoles [3]. Finally, I comment on recent experimental progress to implement synthetic dimensions in semiconductor-superconductor heterostructures [4].
[1] R. L. Klees, G. Rastelli, J. C. Cuevas, and W. Belzig, Microwave spectroscopy reveals the quantum
geometric tensor of topological Josephson matter, Phys. Rev. Lett. 124, 197002 (2020)
[2] H. Weisbrich, R.L. Klees, G. Rastelli, and W. Belzig, Second Chern Number and Non-Abelian Berry
Phase in Superconducting Systems, PRX Quantum 2, 010310 (2021)
[3] H. Weisbrich, M. Bestler, and W. Belzig, Tensor Monopoles in superconducting systems, Quantum
5, 601 (2021)
[4] M. Coraiola, D. Z. Haxell, D. Sabonis, H. Weisbrich, A. E. Svetogorov, M. Hinderling, S. C. ten
Kate, E. Cheah, F. Krizek, R. Schott, W. Wegscheider, J. C. Cuevas, W. Belzig, and F. Nichele, Phaseengineering
the Andreev band structure of a three-terminal Josephson junction, Nat. Commun. 14, 6784 (2023)
- Onsite on Campus Limpertsberg, where you will have the opportunity to meet the speaker over the lunch. Catering is offered from 12:00 PM to all registered participants (BSC Hall). Please register below for the lunch before the 8th of November 2024. Talk at 1:00 PM in BSC 0.03
- Online – through Webex – to give you the opportunity to listen to the talk in case you are travelling or cannot make it onsite at Campus Limpertsberg. Here are the details to join the talk online: