Superconducting electronics are promising candidates for complementing semiconductor electronics. However, a comprehensive suite of superconducting design and simulation tools that is necessary to streamline and automate the design process is either nonexistent or very limited. Here, we describe Synopsys’ advances in the technology computer-aided design (TCAD) front for physics-based simulation of superconducting electronics based on Josephson junctions (JJs). We employ Keldysh–Gor’kov–Nambu Green's function formalism within the context of the self-consistent mean-field theory of Bogoliubov and de-Gennes to simulate the equilibrium and transport properties of JJ-based devices in one dimension. Using these Green's functions, we calculate various electrical properties and effects, including order parameter and proximity effect, current-phase characteristics and current-density distribution for arbitrary temperatures, material properties and composition, and device dimensions. We further expand the TCAD simulator using the Floquet–Keldysh–Gor’kov–Nambu Green's function for calculating current-voltage characteristics of JJs in nonequilibrium and capture various quantum mechanical effects including multiple Andreev reflections (MAR) for constant applied voltage.

中文翻译：

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基于物理学的基于约瑟夫森结的超导电子 TCAD 模拟器

超导电子学是补充半导体电子学的有前途的候选者。然而，简化和自动化设计过程所需的一套全面的超导设计和仿真工具要么不存在，要么非常有限。在这里，我们描述了 Synopsys 在计算机辅助设计 (TCAD) 前沿技术方面的进展，用于基于约瑟夫森结 (JJs) 的超导电子设备进行基于物理的仿真。我们在 Bogoliubov 和 de-Gennes 的自洽平均场理论的背景下采用 Keldysh-Gor'kov-Nambu Green 的函数形式主义来模拟一维基于 JJ 的设备的平衡和传输特性。使用这些格林函数，我们可以计算各种电气特性和效应，包括顺序参数和邻近效应，任意温度、材料特性和成分以及器件尺寸的电流相位特性和电流密度分布。我们使用 Floquet-Keldysh-Gor'kov-Nambu Green 函数进一步扩展了 TCAD 模拟器，用于计算非平衡状态下 JJ 的电流-电压特性，并捕获各种量子力学效应，包括恒定施加电压的多次安德列夫反射 (MAR)。