论文标题
评论“重新审视Dicke模型的相跃迁”
Comment on 'Revisiting the phase transitions of the Dicke model'
论文作者
论文摘要
在Das和Sharma的工作中[Phys。 Rev. A 105，033716（2022）]研究了DICKE模型的相变。它的主要结果是，除了众所周知的量子相变，该模型所表现出的激发态量子相变和热相变，还有上限能量，即$ e _ {*} $，除此之外，模型不再表现出量子混乱的行为以及特征函数的结构。基于这一发现，质疑有关DICKE模型的许多公认的结果。我们认为，这一结果及其所有后果都是由于数值对角线所需的无限维时空间的不当截断而导致的虚假数值效应。
In the work of Das and Sharma [Phys. Rev. A 105, 033716 (2022)] the phase transitions of the Dicke model are studied. Its main result is that, besides the well-known quantum phase transition, excited-state quantum phase transition and thermal phase transition exhibited by the model, there exists an upper bound energy, $E_{*}$, beyond which the model ceases to exhibit quantum chaotic behavior and the structure of the eigenfunctions changes. Based on this finding, a number of well-established results about the Dicke model are called into question. We argue that this result and all its consequences are spurious numerical effects resulting from an improper truncation of the infinite-dimensional Hilbert space necessary for numerical diagonalization.
