Dynamical Symmetries and Symmetry-Protected Selection Rules in Periodically Driven Quantum Systems
Dynamical Symmetries and Symmetry-Protected Selection Rules in Periodically Driven Quantum Systems
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DOI：
10.1103/physrevlett.126.090601
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发表时间：
2021-03-02
影响因子：
8.6
通讯作者：
Cao, Jianshu
中科院分区：
文献类型：
--
作者：
Engelhardt, Georg;Cao, Jianshu
在最近的实验中，光与物质的相互作用已经达到了超强耦合极限，这可以引起周期驱动系统中空间对称性的动力学推广。在这里，我们提出了一个统一的框架，动态对称性保护的选择规则的基础上，弗洛奎响应理论。在这个框架内，我们研究了转动对称性、宇称对称性、粒子空穴对称性、手征对称性和时间反转对称性，以及由此产生的光谱中的选择规则，包括对称保护暗态(SPD)、对称保护暗带和对称诱导的透明度。具体来说，动力学转动对称性和宇称对称性建立了SPD和对称性保护的暗带条件。粒子空穴对称性为对称性相关的Floquit态引入了SPDS，并在准能量交叉处引入了对称性诱导的透明度。手征对称性和时间反转对称性本身并不意味着SPDS条件，但可以组合起来定义粒子-空穴对称性。这些对称性条件是由于对称量子系统与周期驱动同步而产生的相消干涉。我们的预言揭示了当量子系统达到强光物质耦合区域时的新的物理现象，这对于超导量子比特、光学或等离子体场腔中的原子和分子以及光学机械系统都是重要的。
In recent experiments, the light-matter interaction has reached the ultrastrong coupling limit, which can give rise to dynamical generalizations of spatial symmetries in periodically driven systems. Here, we present a unified framework of dynamical-symmetry-protected selection rules based on Floquet response theory. Within this framework, we study rotational, parity, particle-hole, chiral, and time-reversal symmetries and the resulting selection rules in spectroscopy, including symmetry-protected dark states (spDS), symmetry-protected dark bands, and symmetry-induced transparency. Specifically, dynamical rotational and parity symmetries establish spDS and symmetry-protected dark band conditions. A particlehole symmetry introduces spDSs for symmetry-related Floquet states and also a symmetry-induced transparency at quasienergy crossings. Chiral symmetry and time-reversal symmetry alone do not imply spDS conditions but can be combined to define a particle-hole symmetry. These symmetry conditions arise from destructive interference due to the synchronization of symmetric quantum systems with the periodic driving. Our predictions reveal new physical phenomena when a quantum system reaches the strong lightmatter coupling regime, which is important for superconducting qubits, atoms and molecules in optical or plasmonic field cavities, and optomechanical systems.