We report on the Pt doping effect on surface and electronic structure in Ir$_{\mathrm{1-x}}$Pt$_{\mathrm{x}}$Te$_ {\mathrm{2}}$ by scanning tunneling microscopy (STM) and spectroscopy (STS). The surface prepared by cleavage at 4.2 K shows a triangular lattice of topmost Te atoms. The compounds that undergo structural transition have supermodulation with a fixed wave vector $q = \frac{2π}{5a_m}$ (where $a_m$ is the lattice constant in the monoclinic phase) despite the different Pt concentrations. The superconducting compounds show patch structures. The surface of the compound that exhibits neither the superconductivity nor the structural transition shows no superstructure. In all doped samples, the dopant is observed as a dark spot in STM images. The tunneling spectra near the dopant show the change in the local density of state at approximately -200 mV. Such microscopic effects of the dopant give us the keys for establishing a microscopic model of this material.
Visualizing Chiral Edge Modes in Twisted Cuprate Superconductors via Scanning-Probe Quantum Sensing
Georgia Institute of Technology(佐治亚理工学院);Harvard University(哈佛大学);National Institute for Materials Science(国立材料研究所);Brookhaven National Laboratory(布鲁克海文国家实验室);Argonne National Laboratory(阿贡国家实验室)
Visualizing the interplay of dual electronic nematicities in kagome superconductors
University of Science and Technology of China(中国科学技术大学);Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所北京凝聚态物理国家研究中心);CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences(中国科学院理论物理研究所理论物理国家重点实验室);Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China(中国科学技术大学微尺度物质科学国家研究中心);Hefei National Laboratory, University of Science and Technology of China(中国科学技术大学合肥国家实验室)
Evidence of strong correlations at the van Hove singularity in the scanning tunneling spectra of superconducting Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} single crystals
Bridging atomic and mesoscopic length scales with Replica Scanning Tunneling Microscopy: Visualizing the atomic lattice of UTe$_2$ and the atomic scale superconducting gap modulations of FeSe close to micron length scales
Universidad Autónoma de Madrid(马德里自治大学);Universidad del Rosario(罗萨里奥大学)
The study of electronic nematicity in an overdoped (Bi, Pb)$_2$Sr$_2$CuO$_{6+δ}$ superconductor using scanning tunneling spectroscopy
赝能隙(PG)态及其相关的晶胞内对称性破缺一直是铜氧化物超导体研究的热点。虽然在$_2$ $_2$ O $_{8+δ}$,特别是欠掺杂样品中已经研究了向列性,但是它在其他铜酸盐和不同掺杂区域中的行为仍然不清楚。在这里,我们应用扫描隧道显微镜探索过掺杂(Bi,Pb)$_2$ Sr $_2$ CuO $_{6+δ}$与一个大的费米面(FS)。当能量尺度接近PG时,可以看到一个有序的建立及其实空间分布。
Local and macroscopic tunneling spectroscopy of Y(1-x)CaxBa2Cu3O(7-d) films: evidence for a doping dependent is or idxy component in the order parameter
Anyon Bosonization of 2D Fermions and Single Boson Phase Diagram Implied from Experiment on Visualizing Pair Formation in Superconductor Bi_2Sr_2CaCu_2O_{8+δ}
A scanning tunneling microscope for spectroscopic imaging below 90 mK in magnetic fields up to 17.5 T
我们描述了超高真空扫描隧道显微镜的发展和性能的组合极端条件下的超低温和高磁场。我们结合了顶部加载稀释制冷机和标准桶杜瓦瓶与底部加载超导磁体,以实现4.5天的运行时间,这是足够长的时间来执行各种光谱成像测量。为了使有效电子温度更接近混合室温度,我们特别注意滤除射频噪声,以及增强显微镜单元和混合室之间的热连接。通过测量铝的超导能隙谱,我们估计最低有效电子温度在90 mK以下。我们证实了长期稳定的光谱成像测量可视化超导涡旋的铜酸盐超导体Bi $_{2}$ Sr $_{2}$ CaCu $_{2}$ O $_{8+δ}$。
Electron energy-loss spectroscopy study of electron-doping in MgB$_2$
利用扫描透射电子显微镜(STEM)中的电子能量损失谱(EELS)和第一原理电子结构计算研究了电子掺杂的多晶Mg $_{1-x}$ Al $_{x}$(B $_{1-y}$ C $_{y}$)$_2$的电子结构。我们发现硼$K$边缘精细结构的显着变化,这表明随着Mg $_{1-x}$ Al $_{x}$(B $_{1-y}$ C $_{y}$)$_2$的电子掺杂浓度的增加,B $K$边缘的两个带,$σ$和$π$带被同时填充。我们的密度泛函理论计算证实了接近费米能级的$σ$带态的填充,这被认为是导致高掺杂MgB $_2$中超导性的损失,因为这些状态的电子-声子耦合被认为是高超导转变温度的原因。我们的研究结果没有显示出显着的差异,在电子结构的电子掺杂的Mg或B网站,虽然许多超导性能,如$T_c$或H $_{c_2}$有很大的不同,为C和Al掺杂的\MB。这种行为不能令人满意地解释带填充单独,和带间散射等影响被认为是。
Nanoscale interplay of strain and doping in a high-temperature superconductor
最高温度的超导体在纳米尺度上是电子不均匀的,这表明存在一个局部变量,可以利用它来增强超导配对。本文报道了铜氧化物超导体Bi $_2$ Sr $_2$ CaCu $_2$ O $_{8+x}$中局域掺杂与局域应变之间的关系。我们使用扫描隧道显微镜发现,关键的氧掺杂剂是周期性分布的,与局部应变。我们的所有氧掺杂剂的单位细胞内的位置的皮尺度调查提供了一个完整的微观理论的基本结构输入。
Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped Ba(Fe_{1-x}Co_x)_2As_2 Single Crystals using Scanning Tunneling Spectroscopy
Universal $\sqrt{2}\times\sqrt{2}$ structure and short-range charge order at the surfaces of BaFe$_{2-x}$Co$_{x}$As$_{2}$ compounds with various Co doping levels
用扫描隧道显微镜系统地研究了新发现的磷属元素化物超导体BaFe $_{2-x}$ Co $_{x}$ As $_{2}$(x从0到0.32)解理面的结构和电子有序性.所有化合物的表面结构均为$\sqrt{2}\times\sqrt{2}$,结合理论模拟,确定其为Ba层,其中一半Ba原子被剥离.一个普遍的短程电荷秩序被观察到在这个$\sqrt{2}\times\sqrt{2}$表面与一个能隙约30毫电子伏的所有化合物。