论文标题
由于超抗偶联QED中的物质截断而导致的量规无变量
Gauge non-invariance due to material truncation in ultrastrong-coupling QED
论文作者
论文摘要
最近在强耦合QED中探索了由于物质截断而导致的量规不变。我们表明，最近在《自然物理学》中提出的方法15，803（2019）基于不正确的数学断言，因此不能解决规范的非变异性。它产生了新的两级模型，这些模型在不同的衡量中不相等。对于自然物理学15，803（2019）中考虑的机制而言，新的库仑规模模型不准确，为此，多极量子量子兔模型是准确的。在自然物理学中分析的模型15，803（2019）不是由主文本中提供的参数引起的，而是来自多极 - 符号内的截断，然后是应用截断的相位交易原理。更一般而言，该原理可以在任何仪表中截断后应用，并且在所选规格中产生了等效的截断模型类别。属于不同仪表的等效类不是等效的，并且截断的相位变异原理不能提供参数以更喜欢特定类别。通常，最佳类取决于物理状况，包括观测值，参数制度以及正在考虑的场模式。我们还强调，由于近似值，仪表型不与量规不变性的代名词。独立于材料截断子系统预测可以大大不同，具体取决于子系统的理论定义，这些定义受仪表选择控制。这构成了矢量空间相对论的一个例子，这绝不与量规不变相矛盾。但是，在Ultrastrong耦合方案中，这种相对性不再被忽略。
Gauge non-invariance due to material truncation has recently been explored in a number of contexts in strong-coupling QED. We show that the approach proposed recently in Nature Physics 15, 803 (2019) rests on an incorrect mathematical assertion and so does not resolve gauge non-invariance. It produces new two-level models that are not equivalent in different gauges. The new Coulomb-gauge model is inaccurate for the regimes considered in Nature Physics 15, 803 (2019), for which the multipolar-gauge quantum Rabi model is accurate. The models analysed in Nature Physics 15, 803 (2019) do not result from the argument provided in the main text, but instead from truncation within the multipolar-gauge followed by the application of a truncated phase-invariance principle. More generally, this principle can be applied following truncation in any gauge and it yields an equivalence class of truncated models within the gauge chosen. Equivalence classes belonging to different gauges are not equivalent and the truncated phase-invariance principle does not provide an argument to prefer a particular class. In general, the optimal class depends on the physical situation, including the observables, the parameter regime, and the number of field modes being considered. We also emphasise that gauge-ambiguities are not synonymous with gauge non-invariance due to approximations. Independent of material truncation subsystem predictions can be vastly different depending on the theoretical definitions of the subsystems, which are controlled by the gauge choice. This constitutes an example of vector-space relativity that in no way contradicts gauge-invariance. However, within ultrastrong-coupling regimes this relativity can no longer be ignored.
