论文标题
远程光子波动增强了光子介导的电子配对和超导性
Long-range photon fluctuations enhance photon-mediated electron pairing and superconductivity
论文作者
论文摘要
最近，通过腔介导的配对提出了在二维材料中诱导电子超导性的可能性。腔介导的电子电子相互作用是远距离的，它具有两个主要影响：首先，在由绝热光子介导的标准BCS型配对中，超导临界温度在多个一级取决于耦合强度，而不是表征了呼应声子介导的配对的指数依赖性；其次，正如我们在这里所显示的那样，光子波动的效果显着增强。这些通过非绝热光子介导了新型的非BCS型配对过程，这些过程对电子占用不敏感，而是对电子表面的电子分散和寿命。因此，尽管BCS配对的领先温度依赖性来自费米 - 迪拉克分布的平稳，但波动引起的配对的温度依赖性来自电子寿命。对于现实的参数（还包括腔损失），这将导致临界温度，该温度可能比BCS预测大一个数量级以上。此外，有限的平均数量光子（可以通过不连贯泵送腔体实现）增加了波动，并导致临界温度的进一步增强。
Recently, the possibility of inducing superconductivity for electrons in two dimensional materials has been proposed via cavity-mediated pairing. The cavity-mediated electron-electron interactions are long range, which has two main effects: firstly, within the standard BCS-type pairing mediated by adiabatic photons, the superconducting critical temperature depends polynomially on the coupling strength, instead of the exponential dependence characterizing the phonon-mediated pairing; secondly, as we show here, the effect of photon fluctuations is significantly enhanced. These mediate novel non-BCS-type pairing processes, via non-adiabatic photons, which are not sensitive to the electron occupation but rather to the electron dispersion and lifetime at the Fermi surface. Therefore, while the leading temperature dependence of BCS pairing comes from the smoothening of the Fermi-Dirac distribution, the temperature dependence of the fluctuation-induced pairing comes from the electron lifetime. For realistic parameters, also including cavity loss, this results into a critical temperature which can be more than one order of magnitude larger than the BCS prediction. Moreover, a finite average number photons (as can be achieved by incoherently pumping the cavity) adds to the fluctuations and leads to a further enhancement of the critical temperature.
