Dresden 2026 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 82: Cryogenic Detectors and Sensors
TT 82.6: Vortrag
Donnerstag, 12. März 2026, 16:15–16:30, HSZ/0103
Vortex Energy Barriers in Meandering Superconducting Nanowires: Controlling Jitter in SNSPDs via magnetic field and bias currents — •Carlos Alberto Diaz Lopez1, Joachim Ankerhold1, Björn Kubala1, 2, and Ciprian Padurariu1 — 1Institute of Complex Quantum Systems, University of Ulm, Ulm, Germany — 2German Aerospace Center (DLR), Ulm, Germany
We present a theoretical and computational study of vortex dynamics in meandering superconducting nanowires (e.g., SNSPDs). Building upon established methods for computing vortex energies in non-conventional geometries, our work incorporates the effect of screening currents induced by an external magnetic field. We calculate the total Gibbs free energy landscape to determine sets of parameters (Bz, Ibias) to engineer a tunable energy barrier for vortex crossing events. We seek barriers high enough to suppress spontaneous vortex-crossing (the mechanism underlying dark counts and timing jitter) yet remain low enough to permit crossing upon localized perturbations (e.g., a hotspot following single-photon absorption)
This analytical approach is benchmarked against a heuristic approach via simulations of the generalized time-dependent Ginzburg-Landau (gTDGL), performed using the open-source package py-TDGL. Our findings offer a design principle for optimizing operating conditions of SNSPDs to achieve maximal timing resolution and dark-count suppression.
Keywords: Vortex Dynamics; Superconducting Nanowire Single Photon Detector; Gibbs free energy; Energy barrier; Ginzburg-Landau theory