Study on the Behavior of Superconducting Nanostructured Switching Device by the Numerical Calculation

We investigated the properties and switching behavior of superconducting nanostructured device such as nanocryotron using numerical calculation methods. Superconducting nanostructured switching devices such as nanocryotron (nTron) are promising candidates for the interface between the single-flux-quantum (SFQ) circuit and the CMOS memory in building highly integrated superconducting circuits. Although some simulations have been performed, the detailed physics of its operation is not clear. Therefore, we are studying the behavior of superconducting nanostructured devices through numerical simulations using the thermal diffusion equation and the time-dependent Ginzburg-Landau (TDGL) equation. We previously reported on the simulation of a simple T-shaped line with a current confluence of a constant bias current and a short-time gate current. As the next step, we report the simulation on a T-shaped device with a constriction in the channel. We observed the variation in current, temperature, voltage generated in the channel, etc. during switching. Although the simulations in this report are ongoing, they will help analyze and understand the experimental results and are also expected to provide guidelines for device design.