论文标题
评论“约瑟夫森连接中的缺失与存在耗散量子相变的存在”
Comment on "Absence versus Presence of Dissipative Quantum Phase Transition in Josephson Junctions''
论文作者
论文摘要
在最近的一封信中[物理学。莱特牧师。 129，087001，（2022）]，Masuki，Sudo，Oshikawa和Ashida与Josephson Ennction一起研究了Josephson Energy $ e _ {\ rm J} $，并为Energy $ e _ {\ rm C} $充电，被OHMIC OHMIC TRAMPLETION LIWS OHMIC TROVELATION LYTED LIWS CONDANITIA他们的模型包括订单$αe_c$的现实高频截止，通常小于等离子体频率$ w $。作者提出了一个相图，显示出令人惊讶的特征，但在已建立的文献中没有预见[例如。 Schön和Zaikin，物理。报告198，237，（1990）]。对于$ e _ {\ rm j}/e _ {\ rm c} $以上一个值，他们发现连接点仍然对所有$α$保持超导，而低于此值，他们发现绝缘阶段会导致小$α$的重新进入超导性。在此评论中，我们表明他们的数值重归其化组（NRG）的实现是不受控制的，并且没有证据表明在PRL 129，087001的图1A中显示的相图中的重分超导性。
In a recent Letter [Phys. Rev. Lett. 129, 087001, (2022)], Masuki, Sudo, Oshikawa, and Ashida studied a Josephson junction, with Josephson energy $E_{\rm J}$ and charging energy $E_{\rm C}$, shunted by an ohmic transmission line with conductance $α(2e)^2/h$. Their model includes a realistic high frequency cutoff of order $αE_c$, that is typically smaller than the plasma frequency $W$. The authors present a phase diagram showing surprising features, not anticipated in the established literature [eg. Schön and Zaikin, Phys. Reports 198, 237, (1990)]. For $E_{\rm J}/E_{\rm C}$ above a certain value, they find that the junction remains superconducting for all $α$, while below this value, they find that the insulating phase leads to re-entrant superconductivity at small $α$. In this Comment, we show that their Numerical Renormalization Group (NRG) implementation is uncontrolled, and that there is no evidence for the re-entrant superconductivity in the phase diagram presented in Fig. 1a of PRL 129, 087001.
