Title:	Simulations of superconducting nanostructures
DNr:	SNIC 2022/5-541
Project Type:	SNIC Medium Compute
Principal Investigator:	Jack Lidmar <jlidmar@kth.se>
Affiliation:	Kungliga Tekniska högskolan
Duration:	2022-11-29 – 2023-12-01
Classification:	10304
Homepage:	https://www.kth.se/profile/jack/
Keywords:

Abstract

This project studies models of superconducting nanostructures using large scale simulations. In particular, we will study meandering nanowires, which act as superconducting single photon detectors (SSPDs). When a photon hits the wire the superconductivity is locally suppressed, which triggers a vortex to nucleate and cross the nanowire. This will in turn cause more vortices to cross and lead to a detectable voltage pulse. This complicated dynamics is poorly understood and depend on many different variables, e.g., thermal fluctuations, disorder, and geometrical details of the device. Using 2D time-dependent Ginzburg-Landau simulations we will simulate the detection process and current crowding effects at the turnarounds of the meander, with the goal to optimize various performance measures of the detectors. At the same time, we are collaborating with experimentalists who are designing and measuring such SSPDs. A variety of different computation and simulation methods are used, e.g., finite volume solutions of stochastic time-dependent PDEs and SDEs, and Monte Carlo simulations.