Description:

Modern quantum technologies frequently use superconducting materials that are experimentally realized as thin-film circuits or hybrid structure operating in the mesoscopic regime. On this length scale, the superconducting order may be influenced by various finite-size or surface effects, many of which are not yet fully understood. This knowledge gap, combined with the great promise of modern quantum technologies, makes mesoscopic superconductivity a ripe field for fundamental research. To study such systems, we are developing a new tool combining the quasiclassical theory of superconductivity with high-performance computing on Graphics Processing Units [1]. In this talk, I will show you how this tool can be used to do real-time visualization of vortex dynamics, and how it was used to discover a new superconducting order in which translational symmetry is spontaneously broken at pair-breaking interfaces [2]. It will be shown how this order gives rise to a spontaneous superflow with a topological pattern of sources and sinks [3,4], and experimental verification will be discussed. Finally, I will show you how the effect can be derived through a non-local Ginzburg-Landau coefficient that might lead to similar transitions in other condensed matter systems.

[1] P. Holmvall, Licentiate thesis: Modeling mesoscopic unconventional superconductors (2017)
[2] M. Håkansson, T. Löfwander, and M. Fogelström, Nat. Phys. 11, 755 (2015).
[3] P. Holmvall, A. Vorontsov, M. Fogelström, and T. Löfwander, Nat. Commun. 9, 2190 (2018)
[4] P. Holmvall, T. Löfwander, and M. Fogelström, J. Phys.: Conf. Ser. 969, 012037 (2018).

Patric Holmvall, Chalmers University of Technology

Host: James Sauls

Keywords: Physics, Astronomy, Condensed Matter