标题： 光驱动“超导性”的通用方法通过预形成对 显示英文标题

标题： Universal approach to light driven "superconductivity" via preformed pairs

摘要： 虽然有许多不同的机制被提出以理解光诱导“超导性”背后的物理，但似乎在观察到这种现象的材料类别中存在共同点，即存在强烈的配对关联，这些关联存在于正常态中。 在这里我们认为，Eliashberg的原始想法适用于这种赝能隙相，并且在辐射照射下，费米子被重新分布到更高的能量，这些能量对配对的影响较小。 结果是一个光诱导的状态，其中几乎凝聚的费米子对数量显著增强。 在这个相中，由于交流电导率$\sigma(\omega) = \sigma_1(\omega) + i \sigma_2(\omega)$主要由玻色子贡献主导，因此可以使用传统的（Aslamazov Larkin）涨落理论进行计算。 因此，我们观察到了预期的光诱导“超导”状态的特征指纹，即在$\sigma_2$中具有$1/\omega$的依赖关系，与所谓的光增强（Drude）电导率情景的数据拟合质量相同。 然而，在这里我们对运输中出现的特征低能尺度有了微观理解，并且该尺度必然依赖于温度。 这种方法还为最近观察到的同时反磁涨落提供了见解。 我们的计算表明，这些强配对超导体中观察到的光诱导相仅具有短程相位相干性，而没有长程超导序。 显示英文摘要

摘要： While there are many different mechanisms which have been proposed to understand the physics behind light induced ``superconductivity", what seems to be common to the class of materials in which this is observed are strong pairing correlations, which are present in the normal state. Here we argue, that the original ideas of Eliashberg are applicable to such a pseudogap phase and that with exposure to radiation the fermions are redistributed to higher energies where they are less deleterious to pairing. What results then is a photo-induced state with dramatically enhanced number of nearly condensed fermion pairs. In this phase, because the a.c. conductivity, $\sigma(\omega) = \sigma_1(\omega) + i \sigma_2(\omega)$, is dominated by the bosonic contribution, it can be computed using conventional (Aslamazov Larkin) fluctuation theory. We, thereby, observe the expected fingerprint of this photoinduced ``superconducting" state which is a $1/\omega$ dependence in $\sigma_2$ with fits to the data of the same quality as found for the so-called photo-enhanced (Drude) conductivity scenario. Here, however, we have a microscopic understanding of the characteristic low energy scale which appears in transport and which is necessarily temperature dependent. This approach also provides insight into recent observations of concomitant diamagnetic fluctuations. Our calculations suggest that the observed light-induced phase in these strongly paired superconductors has only short range phase coherence without long range superconducting order.