Possible Enhancement of Superconductivity in Ambient-Pressure La$_3$Ni$_2$O$_7$ Thin Film
Southern University of Science and Technology（南方科技大学）；Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area（粤港澳大湾区量子科学中心）；State Key Laboratory of Quantum Functional Materials, Department of Physics, and Guangdong Basic Research Center of Excellence for Quantum Science, Southern University of Science and Technology (SUSTech)（南方科技大学量子功能材料国家重点实验室、物理系及广东省基础科研卓越中心）
As an unconventional superconducting system capable of reaching 60 K under ambient pressure, the La$_3$Ni$_2$O$_7$ thin film superconductor has recently become a focal point in the field of superconductivity, calling for further theoretical exploration of its possible pairing mechanisms. In this work, we employ the fluctuation exchange (FLEX) approximation to systematically analyze the superconducting properties of a previously proposed two-site, two-orbital model for the La$_3$Ni$2$O$7$ thin film in the weakly correlated regime, with particular emphasis on its dependence on hole doping. Through a more detailed examination of the Fermi-surface topology, we find that when a $δ$ pocket composed of the $d_{z^{2}}$ antibonding orbital emerges near the $Γ$ point, its nesting with the $γ$ pocket, together with the nesting between the $α$ and $β$ pockets, leads to a mutual enhancement of $s{\pm}$-wave pairing at the corresponding wave vector. Furthermore, we propose that this nesting-driven enhancement of spin-fluctuation-induced pairing may provide a viable mechanism for enhancing superconductivity.
Evidence of Inhomogeneous Superconductivity in FeTe$_{1-x}$Se$_x$ Thin Film Using Scotch-Tape Method
我们用透明胶带法制备了FeTe $_{1-x}$ Se $_x$薄膜。虽然这些薄膜是由相同的块体样品制备的，但它们的超导性彼此不同。结果清楚地表明了FeTe $_{1-x}$ Se $_x$的非均匀超导电性。差异来自于由于过量Fe浓度引起的不均匀性。低过量Fe的薄膜的电阻率显示出良好的超导性，具有陡峭的超导转变宽度和更多的各向同性超导电性。
Short commentary on comparing previous claim of RT superconductivity with the data of arXiv:1807.08572, "Evidence for Superconductivity at Ambient Temperature and Pressure in Nanostructures"
Ambient-pressure 151-K superconductivity in HgBa2Ca2Cu3O8+δ via pressure quench
Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH)（休斯顿大学物理系及超导德州中心）；Enterprise Science Fund, Intellectual Ventures（智力资本企业科学基金）；X-ray Science Division, Argonne National Laboratory（阿贡国家实验室X射线科学部）
Thickness dependence of superconductivity and superconductor-insulator transition in ultrathin FeSe films on SrTiO3(001) substrate
SrTiO 3（001）（STO）衬底上单胞FeSe薄膜的界面增强高温超导性是近年来凝聚态物理和材料科学研究的热点。本文利用非原位输运测量方法研究了STO衬底上不同厚度的FeSe超薄膜的超导电性。我们发现，开始超导转变温度（Tc）随FeSe薄膜厚度的增加而降低，这是在传统的超导薄膜中通常观察到的行为相反。通过对5 μ C FeSe薄膜的系统后退火，我们观察到了绝缘体到超导体的转变，根据相应的霍尔测量，在低温下伴随着占主导地位的载流子从空穴到电子的符号变化。
Superconductivity Induced in Iron Telluride Films by Low Temperature Oxygen Incorporation
我们报告的超导诱导膜的非超导，反铁磁母体材料FeTe的低温氧掺入在可逆的方式。X射线吸收表明，氧掺杂改变了名义Fe价态从2+在非超导状态，主要是3+在超导状态。因此，氧掺杂的FeTe中的超导性发生在与更常见的FeTe $_{1-x}$ Se $_x$完全不同的电荷和应变状态下。这项工作也提出了一个方便的路径进行掺杂实验原位与许多测量技术。
Superconductivity at the metal-insulator phase boundary in a bulk nickelate at ambient pressure
Argonne National Laboratory（阿贡国家实验室）；University of Illinois Chicago（伊利诺伊大学芝加哥分校）；School of Physics, Southeast University（东南大学物理学院）；Norfolk State University（诺福克州立大学）
Singlet Reservoir Theory of Ambient Tc Granular Superconductivity in Monovalent Metal Nanostructures
单价金属含有s电子的半填充带（HFB）。为了强调2D和1D单价系统中HFB中库仑排斥的重要性，我们概述了Thapa和Pandey（2018）在Au-Ag纳米结构中报告的环境温度颗粒超导性的理论（2018）（由Thapa等人更新，2019年）。为了使我们的理论更加清晰，我们建议\textit{Coulomb repulsions in certain structurally perturbed regions (atomic clusters, stacking faults, grain boundaries etc.) create nanoscale reservoirs of singlet electron pairs} .这些低维补丁杂交到背景的3D jeletron金属，并通过邻近约瑟夫森效应产生观察到的环境Tc颗粒超导性。利用排斥哈伯德模型，我们显示了单重态水库和掺杂莫特绝缘体的物理存在。所需的电荷转移由不同的电负性引起。我们的理论预测\textit{all elemental monovalent (alkali, Cu, Ag and Au) metals, under suitable structural perturbations, are likely to exhibit ambient temperature superconductivity}。
Signatures of room-temperature superconductivity emerging in two-dimensional domains within the new Bi/Pb-based ceramic cuprate superconductors at ambient pressure
Superconductivity above 28 K in single unit cell FeSe films interfaced with GaO$_{2-δ}$ layer on NdGaO$_{3}$(110)
我们在以Ga O $_{2-δ}$为终端的钙钛矿型Nd Ga O $_{3}$（110）衬底上制备了单晶胞FeSe薄膜，并对FeTe保护膜进行了非原位输运和扫描透射电子显微镜测量。我们的实验测量表明，与GaO $_{2-δ}$层界面的单晶胞FeSe薄膜是通过界面电荷转移进行电子掺杂的。最重要的是，这种类型的异质结构可以主机界面增强超导性的起始温度约为28 K，这是远远高于8 K的值在体FeSe。我们的工作表明，FeSe/GaO $_{2-δ}$可以作为一个与FeSe/TiO $_{2-δ}$家族相比较的平台，用于理解界面增强高温超导性的机制。
Tuning Chemical Precompression: Theoretical Design and Crystal Chemistry of Novel Hydrides in the Quest for Warm and Light Superconductivity at Ambient Pressures
