ARC: An open-source library for calculating properties of alkali Rydberg atoms

We present an object-oriented Python library for computation of properties of highly-excited Rydberg states of alkali atoms. These include single-body effects such as dipole matrix elements, excited-state lifetimes (radiative and black-body limited) and Stark maps of atoms in external electric fields, as well as two-atom interaction potentials accounting for dipole and quadrupole coupling effects valid at both long and short range for arbitrary placement of the atomic dipoles. The package is cross-referenced to precise measurements of atomic energy levels and features extensive documentation to facilitate rapid upgrade or expansion by users. This library has direct application in the field of quantum information and quantum optics which exploit the strong Rydberg dipolar interactions for two-qubit gates, robust atom-light interfaces and simulating quantum many-body physics, as well as the field of metrology using Rydberg atoms as precise microwave electrometers.本文提出一款面向对象的Python库，用于计算碱金属原子高激发里德伯态（Rydberg state）的各项性质。该库可计算单体效应相关内容，包括偶极矩阵元（dipole matrix element）、激发态寿命（涵盖辐射受限与黑体辐射受限两种情形）以及外电场下原子的斯塔克图谱（Stark map）；同时支持双原子相互作用势的计算，该势模型考虑了偶极与四极耦合效应，在原子偶极子任意排布的场景下，均可适用于长程与短程相互作用。本软件包与原子能级的精确测量结果交叉验证，并配备详尽的文档，以便用户快速进行升级或拓展。该库可直接应用于两大领域：其一为量子信息与量子光学领域，依托强里德伯偶极相互作用实现两量子比特门、构建稳健的原子-光界面以及模拟量子多体物理；其二为计量学领域，利用里德伯原子作为高精度微波电场计开展相关研究。