Abstract

In this paper, we study the spontaneous emission spectra and the emission decay rates of a simplest atom system that exhibits sub- and superradiant properties: a system which consists of two artificial atoms (superconducting qubits) embedded in a one-dimensional open waveguide. The calculations are based on the method of the transition operator which was firstly introduced by R. H. Lehmberg to theoretically describe the spontaneous emission of two-level atoms in a free space. We obtain the explicit expressions for the photon radiation spectra and the emission decay rates for different initial two-qubit configurations with one and two excitations. For every initial state we calculate the radiation spectra and the emission decay rates for different effective distances between qubits. In every case, a decay rate is compared with a single qubit decay to show the superradiant or subradiant nature of a two-qubit decay with a given initial state.

Graphic Abstract

中文翻译：

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电路量子电动力学中双量子位系统的超辐射发射光谱

摘要

在本文中，我们研究了表现出亚和超辐射特性的最简单原子系统的自发发射光谱和发射衰减率：该系统由嵌入一维开放波导中的两个人造原子（超导量子比特）组成。计算基于 RH Lehmberg 首次引入的跃迁算子方法，从理论上描述了自由空间中两能级原子的自发发射。我们获得了具有一个和两个激发的不同初始双量子比特配置的光子辐射光谱和发射衰减率的显式表达式。对于每个初始状态，我们计算量子位之间不同有效距离的辐射光谱和发射衰减率。在任何情况下，

图形摘要