论文标题
量表原理和量子量度不变性两级系统
Gauge Principle and Gauge Invariance in Quantum Two-Level Systems
论文作者
论文摘要
量子兔模型是两级系统和电磁谐振器的量化单模式之间耦合的广泛描述。已经提出了有关该模型量规不变性的问题。当光 - 摩擦互动达到所谓的Ultrastrong耦合方案时，这些问题就变得显而易见。最近，引入了一个改良的量子狂犬模型，能够在任何相互作用方面提供量规不变的物理结果[自然物理学15，803（2019）]。在这里，我们根据量规原理的两国系统的实现提供了该结果的替代推导，这是量子场理论中所有基本相互作用的原理。所采用的程序可以被视为用于实施晶格量规理论中量规原理的一般方法的两个站点版本。采用此方法，我们还获得了不对称两态系统的规范不变量子狂犬模型，以及超出偶极子近似的多模式量规量子兔模型。
The quantum Rabi model is a widespread description for the coupling between a two-level system and a quantized single mode of an electromagnetic resonator. Issues about this model's gauge invariance have been raised. These issues become evident when the light-matter interaction reaches the so-called ultrastrong coupling regime. Recently, a modified quantum Rabi model able to provide gauge-invariant physical results in any interaction regime was introduced [Nature Physics 15, 803 (2019)]. Here we provide an alternative derivation of this result, based on the implementation in two-state systems of the gauge principle, which is the principle from which all the fundamental interactions in quantum field theory are derived. The adopted procedure can be regarded as the two-site version of the general method used to implement the gauge principle in lattice gauge theories. Applying this method, we also obtain the gauge-invariant quantum Rabi model for asymmetric two-state systems, and the multi-mode gauge-invariant quantum Rabi model beyond the dipole approximation.
