Title: Eigenvector continuation for emulating and extrapolating two-body resonances Show Chinese title

Title: 特征向量延拓用于模拟和外推两体共振

Abstract: The study of open quantum systems (OQSs), i.e., systems interacting with an environment, impacts our understanding of exotic nuclei in low-energy nuclear physics, hadrons, cold-atom systems, or even noisy intermediate-scale quantum computers. Such systems often exhibit resonance states characterized by energy positions and dispersions (or decay widths), the properties of which can be difficult to predict theoretically due to their coupling to the continuum of scattering states. Dealing with this phenomenon poses challenges both conceptually and numerically. For that reason, we investigate how the reduced basis method known as eigenvector continuation (EC), which has emerged as a powerful tool to emulate bound and scattering states in closed quantum systems, can be used to study resonance properties. In particular, we present a generalization of EC that we call conjugate-augmented eigenvector continuation, which is based on the complex-scaling method and designed to predict Gamow-Siegert states, and thus resonant properties of OQSs, using only bound-state wave functions as input. Show Chinese abstract

Abstract: 开放量子系统（OQSs）的研究，即与环境相互作用的系统，对我们理解低能核物理中的奇特核、强子、冷原子系统，甚至噪声中间规模量子计算机都有影响。 这类系统常常表现出由能量位置和展宽（或衰变宽度）表征的共振态，由于它们与散射态连续谱的耦合，这些性质在理论上可能难以预测。 处理这种现象在概念上和数值上都带来了挑战。 因此，我们研究了被称为特征向量延拓（EC）的约化基方法，该方法作为一种强大的工具，在封闭量子系统中模拟束缚态和散射态，探讨如何用它来研究共振性质。 特别是，我们提出了一种称为共轭增强特征向量延拓的广义方法，该方法基于复尺度法，旨在仅使用束缚态波函数作为输入来预测Gamow-Siegert态，从而推导出OQSs的共振性质。