We conduct local magnetic measurements on superconducting thin-film samples of Sr$\mathrm{_2}$RuO$\mathrm{_4}$ using scanning Superconducting Quantum Interference Device (SQUID) susceptometry. From the diamagnetic response, we extract the magnetic penetration depth, $λ$, which exhibits a quadratic temperature dependence at low temperatures. Although a quadratic dependence in high-purity bulk samples has been attributed to non-local electrodynamics, our analysis suggests that in our thin-film samples the presence of scattering is the origin of the quadratic dependence. While we observe micron-scale variations in the diamagnetic response and superconducting transition temperature, the form of the temperature dependence of $λ$ is independent of position. Finally, we characterize flux trapping in superconducting rings lithographically fabricated from the thin films, paving the way to systematic device-based tests of the superconducting order parameter in Sr$\mathrm{_2}$RuO$\mathrm{_4}$.
Quantum Oscillations of $\mathrm{Sr}_2\mathrm{RuO}_4$ under c-Axis Uniaxial Stress
Max Planck Institute for Chemical Physics of Solids(马克斯·普朗克固体化学物理研究所);Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews(圣安德鲁斯大学物理与天文学学院苏格兰大学物理联盟);National Institute for Materials Science(国立材料研究所);Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology(卡尔斯鲁厄理工学院量子材料与技术研究所)
Ultrasonic Observation of Slowing Down of Multipole Fluctuations in Sr$_2$RuO$_4$
Tokyo University of Science(东京科学大学);Niigata University(新潟大学);Toyama Prefectural University(富山県立大学);National Institute of Advanced Industrial Science and Technology (AIST)(产业技术综合研究所)
Growth of superconducting epitaxial films of sulfur substituted FeSe via pulsed laser deposition
本文报道了用脉冲激光沉积法成功地生长了含$x \leq 0.43$的FeSe $_{1-x}$ S $_x$外延薄膜。随着S含量的增加,超导转变温度$T_{\mathrm s}$系统地降低,并且超导转变温度$T_{\mathrm c}$显示出逐渐降低,即使当$x$超过超导终点(NEP)时,类似于体样品。对于具有大$x$的膜,在$ρ$-$T$曲线中观察到新的扭结异常,这可能是由于磁性转变。FeSe $_{1-x}$ S $_x$薄膜的相图与FeSe $_{1-y}$ Te $_y$薄膜的相图相反,其显示在NEP处$T_{\mathrm c}$快速增加。结果表明,在FeSe体系中,超导电性与超有序度之间的关系并不普遍,这表明在这些材料中,超导电性与超有序度之间的关系并不是主要的.
Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe$_{1-x}$Te$_{x}$ thin films
我们证明了成功的制造与$0 \le x \le 1$的FeSe $_{1-x}$ Te $_{x}$薄膜的CaF $_2$衬底上,包括区域的$0.1 \le x \le 0.4$,这是众所周知的“相分离区”,通过脉冲激光沉积,这是一种非平衡的方法。在由此产生的薄膜中,我们观察到一个巨大的增强的超导转变温度,$T_\mathrm{c}$,在该区域的$0.1 \le x \le 0.4$:最大值达到23 K,这是大约1.5倍大的散装样品的FeSe $_{1-x}$ Te $_{x}$报告的值。我们提出了一个完整的相图FeSe $_{1-x}$ Te $_{x}$薄膜。令人惊讶的是,在$0.1<x<0.2$处观察到$T_\mathrm{c}$的突然抑制,而对于$0.2 \le x < 1$,$T_\mathrm{c}$随着$x$的降低而增加。也就是说,在$x=0-0.1$和$x \ge 0.2$中实现的超导性之间存在明显的差异。为了获得具有高$T_\mathrm{c}$的FeSe $_{1-x}$ Te $_{x}$薄膜,发现Te含量$x$和面内晶格应变的控制是关键因素。
Positive and negative chemical pressure effects investigated in electron-doped FeSe films with an electric-double-layer structure
通过在LaAlO $_3$衬底上制备FeSe单晶薄膜,研究了电子掺杂FeSe中的化学压力效应。我们的方法使电子掺杂的FeSe的运输测量。通过施加5V的栅极电压进行电子掺杂增加了具有$0 \leq x \leq 0.4$和$0 \leq y \leq 0.25$的FeSe $_{1-x}$ Te $_x$和FeSe $_{1-y}$ S $_y$膜的$T_{\mathrm c}$,而e掺杂的$x=0.5$膜显示出比未掺杂的膜更低的$T_{\mathrm c}$。正压力和化学压力均抑制e掺杂FeSe的$T_{\mathrm c}$。所得到的超导相图在掺杂的样品是相当不同的,在未掺杂的样品。这可能表明未掺杂和e掺杂系统之间的超导机制是不同的。或者,这可能是解释的情况下,在电子掺杂的样品中的电子顺序。
Systematic Comparison of Eight Substrates in the Growth of FeSe$_{0.5}$Te$_{0.5}$ Superconducting Thin Films
本文研究了在八种不同衬底上生长的FeSe $_{0.5}$ Te $_{0.5}$薄膜的晶体结构和超导性质。超导性与晶格失配无关,而是与面内取向程度和晶格参数比$c/a$相关。在MgO和LaAlOPDMATHABMO($T_\mathrm{c}^\mathrm{zero}$为9.5 K)上的薄膜中观察到最好的超导性能。TEM观察表明,在衬底表面的非晶类层的存在或不存在起着关键作用,在确定的结构和超导性能的生长薄膜。
Superconductivity and Electronic Structures of Nickelate Thin Film Superstructures
Southern University of Science and Technology(南方科技大学);University of Science and Technology of China(中国科学技术大学);Shanghai Jiao Tong University(上海交通大学);Tsinghua University(清华大学)
Superconducting Dome in $\mathrm{La}_{3-x}\mathrm{Sr}_{x}\mathrm{Ni}_{2}\mathrm{O}_{7-δ}$ Thin Films
National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University(南京大学工程与应用科学学院,固体微结构物理国家重点实验室,人工功能材料江苏省重点实验室);Collaborative Innovation Center of Advanced Microstructures, Nanjing University(南京大学先进微结构协同创新中心)
A Study of Superconducting Behavior in Ruthenium Thin Films
University of Maryland(马里兰大学);Clemson University(克莱姆森大学);IBM T. J. Watson Research Center(IBM托马斯·J·沃森研究中心);Laboratory for Physical Sciences, University of Maryland(马里兰大学物理科学实验室)
Giant Room-Temperature Third-Order Electrical Transport in a Thin-Film Altermagnet Candidate
School of Materials Science and Engineering, Beihang University(北京航空航天大学材料科学与工程学院);School of Physics, Beihang University(北京航空航天大学物理学院);State Key Laboratory of Tropic Ocean Engineering Materials and Materials Evaluation, Beihang University(北京航空航天大学热带海洋工程材料与材料评价国家重点实验室);National Synchrotron Radiation Laboratory, University of Science and Technology of China(中国科学技术大学国家同步辐射实验室);Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences(中国科学院合肥物质科学研究院高磁场中心安徽低能量子材料与器件重点实验室)
Multimodal Terahertz Spectroscopy of the Pairing Symmetry and Normal-State Pseudogap in (La,Pr)$_3$Ni$_2$O$_7$ Films
Center for High Pressure Science and Technology Advanced Research(高压科学实验中心);International Center for Quantum Materials, School of Physics, Peking University(北京大学物理学院量子材料国际中心);Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(粤港澳大湾区量子科学中心);Department of Physics and Guangdong Basic Research Center of Excellence for Quantum Science, Southern University of Science and Technology(南方科技大学物理系及广东省量子科学基础研究中心);Beijing Academy of Quantum Information Sciences(北京量子信息科学研究院);Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所凝聚态物理国家实验室);Tsung-Dao Lee Institute, Department of Physics and Astronomy, Shanghai Jiao Tong University(上海交通大学物理与天文学院李政道研究所);Department of Physics, Tsinghua University(清华大学物理系)
Pressure-induced superconductivity in epitaxially-stabilized Pr$_3$Ni$_2$O$_7$ films
The University of Tokyo(东京大学);RIKEN Center for Emergent Matter Science (CEMS)(理化学研究所新兴物质科学中心);Institute for Materials Research (IMR), Tohoku University(东北大学物质材料研究机构);Advanced Institute for Materials Research (WPI-AIMR), Tohoku University(东北大学先进物质材料研究机构);Tokyo College, The University of Tokyo(东京大学东京学院)