A5069844132- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Rare-earth and actinide compounds
- Quantum and electron transport phenomena
- Superconductivity in MgB2 and Alloys
- Topological Materials and Phenomena
- Magnetic and transport properties of perovskites and related materials
- Particle accelerators and beam dynamics
- Advanced Condensed Matter Physics
- Magnetic properties of thin films
- Electronic and Structural Properties of Oxides
- Advanced Chemical Physics Studies
- Surface and Thin Film Phenomena
- 2D Materials and Applications
- Fluid Dynamics and Turbulent Flows
- Diamond and Carbon-based Materials Research
- Magnetic Properties of Alloys
- Working Capital and Financial Performance
- Advanced Algorithms and Applications
- Spam and Phishing Detection
- Chemical and Physical Properties in Aqueous Solutions
- Sentiment Analysis and Opinion Mining
- Text and Document Classification Technologies
- Gyrotron and Vacuum Electronics Research
- Microwave Engineering and Waveguides
Ames National Laboratory
2019-2025
Iowa State University
2019-2025
Government of the United States of America
2024
Sri Lanka Institute of Information Technology
2023
Sri Lanka Technological Campus
2023
Kathmandu College of Management
2023
Tribhuvan University
2017
This paper presents a systematic experimental study of the impact disorder induced by electron irradiation on superconducting phase Dirac semimetal PdTe2. Using recently derived generalized version Anderson theorem, authors obtain quantitative constraints pairing state. leaves an unconventional as most natural candidate order.
The effects of 2.5-MeV electron irradiation were studied in the superconducting phase single crystals ${\mathrm{LaNiGa}}_{2}$, using measurements electrical transport and radio-frequency magnetic susceptibility. London penetration depth is found to vary exponentially with temperature, suggesting a fully gapped Fermi surface. inferred superfluid density close that single-gap weak-coupling isotropic $s\text{\ensuremath{-}}\mathrm{wave}$ superconductor. Superconductivity extremely robust...
We report combined experimental and theoretical analysis of superconductivity in $\mathrm{CaK}{({\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Ni}}_{x})}_{4}{\mathrm{As}}_{4}$ (CaK1144) for $x=0$, 0.017, 0.034. To obtain the superfluid density $\ensuremath{\rho}={\left[1+\mathrm{\ensuremath{\Delta}}{\ensuremath{\lambda}}_{L}(T)/{\ensuremath{\lambda}}_{L}(0)\right]}^{\ensuremath{-}2}$, temperature dependence London penetration depth $\mathrm{\ensuremath{\Delta}}{\ensuremath{\lambda}}_{L}(T)$ was...
Superconducting quantum circuits (SQC) are one of the most promising hardware platforms for computing, yet their performance is currently limited by presence various structural defects inside circuit's structure. Despite impressive progress in past decade, a precise understanding origin these from fabrication processes and impact on coherence still lacking. In this study, we performed comprehensive investigation microstructure, superconductivity, resonator quality factor Nb films deposited...
The London penetration depth $\ensuremath{\lambda}(T)$ was measured in a single crystal of ${\mathrm{V}}_{3}\mathrm{Si}$. superfluid density obtained from this measurement shows distinct signature two almost decoupled superconducting gaps. This alone is insufficient to distinguish between ${s}_{\ifmmode\pm\else\textpm\fi{}}$ and ${s}_{++}$ pairing states, but it can be achieved by studying the effect controlled nonmagnetic disorder on transition temperature ${T}_{c}$. For purpose, same...
$\mathrm{Eu}{\mathrm{Cd}}_{2}{\mathrm{As}}_{2}$ is an antiferromagnetic semimetal that can host nontrivial topological properties, depending upon its magnetic state and excitations. Here, we report the synthesis characterization of $\mathrm{Eu}{({\mathrm{Cd}}_{1\ensuremath{-}x}{\mathrm{Ag}}_{x})}_{2}{\mathrm{As}}_{2}$ ${\mathrm{Eu}}_{1\ensuremath{-}y}{\mathrm{Na}}_{y}{\mathrm{Cd}}_{2}{\mathrm{As}}_{2}$, study evolution nature order with doping. Temperature-substitution phase diagrams are...
Niobium is one of the most studied superconductors, both theoretically and experimentally. It tremendously important for applications, it has highest superconducting transition temperature, ${T}_{c}=9.32$ K, all pure metals. In addition to power applications in alloys, niobium used sensitive magnetosensing, radio-frequency cavities, and, more recently, as circuit metallization layers qubits. A detailed understanding its electronic structure, especially normal state anisotropies, crucial...
Niobium thin films on silicon substrate used in the fabrication of superconducting qubits have been characterized using scanning and transmission electron microscopy, electrical transport, magnetization, London penetration depth - based quasiparticle spectroscopy, real-space real-time magneto-optical imaging. We study niobium to provide an example a comprehensive analytical set that may benefit circuits such as those quantum computers. The transition temperature ${T}_{c}=9.35$ K fairly clean...
We study the evolution of temperature-dependent resistivity with controlled point-like disorder induced by 2.5 MeV electron irradiation in stoichiometric compositions "3-4-13" stannides, $(\text{Ca,Sr})_{3}(\text{Ir,Rh})_{4}\text{Sn}_{13}$.Three these cubic compounds exhibit a microscopic coexistence charge-density wave (CDW) order and superconductivity (SC), while $\text{Ca}_{3}\text{Rh}_{4}\text{Sn}_{13}$ does not develop CDW order. As expected, transition temperature, $T_{\text{CDW}}$, is...
The intrinsically superconducting Dirac semimetal <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mn>2</a:mn><a:mi>M</a:mi><a:mtext>−</a:mtext><a:msub><a:mi>WS</a:mi><a:mn>2</a:mn></a:msub></a:mrow></a:math> is a promising candidate for realizing proximity-induced topological superconductivity in its protected surface states. A precise characterization of the bulk state essential to understand nature system. Here, we report detailed experimental study temperature-dependent...
We study the effects of flux creep on linear AC response vortex lattice in a low-pinning Ca$_3$Ir$_4$Sn$_13$ superconductor by measuring Campbell penetration depth, $\lambda_\rm \scriptscriptstyle C(T,H,t)$. Thermal fluctuations release vortices from shallow pinning sites, only for them to become re-trapped deeper potential wells, causing an initial increase effective Labusch parameter, which is proportional well depth. This effect cannot be detected conventional magnetic relaxation...
Abstract Single crystals of the quasi-skutterudite compounds Ca 3 (Ir 1-x Rh x ) 4 Sn 13 (3–4–13) were synthesized by flux growth and characterized x-ray diffraction, energy dispersive spectroscopy, magnetization, resistivity, radio frequency magnetic susceptibility techniques. The coexistence competition between charge density wave (CDW) superconductivity was studied varying Rh/Ir ratio. superconducting transition temperature, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract The effect of annealing on the superconducting properties niobium single crystals was studied using optical, magnetic, and scanning tunneling microscopy (STM) methods. Pieces same crystal boule were before after at 800 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msup><mml:mrow/><mml:mo>∘</mml:mo></mml:msup><mml:mtext>C</mml:mtext></mml:mrow></mml:math> , 1400 near melting point (2477 ). initial samples had a high hydrogen content...
London and Campbell penetration depths were measured in single crystals of the endohedral gallide cluster superconductor, Mo _8 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi/><mml:mn>8</mml:mn></mml:msub></mml:math> Ga _41 display="inline"><mml:msub><mml:mi/><mml:mn>41</mml:mn></mml:msub></mml:math> . The full temperature range superfluid density, \rho_s(T)...
Abstract The London penetration depth, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>λ</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>T</mml:mi> stretchy="false">)</mml:mo> </mml:mrow> </mml:math> , was measured in various forms of niobium, including foils, thin films, single crystals, and samples from superconducting radio-frequency (SRF) cavities. We observed a significant difference at low temperatures, <mml:mo><</mml:mo>...
AbstractFall armyworm (Spodoptera frugiperda) is an invasive pest in South Asia. The current paper documents farmers' perceptions of fall India, Pakistan, Sri Lanka, and Nepal explores the management practices adopted by farmers. A structured survey was conducted with 526 farmers regarding cropping practices, identification its damage, management, capacity-building activities, support from government non-government extension services. results suggested that most reported very high to...
Spam in Short Message Service(SMS) is a serious issue that impacts mobile phone consumers all around the world. Many strategies have been applied using several deep learning and machine techniques to overcome these issues. The bagging approach used study combine four different algorithms, namely RVM, SVM, Naive Bayes, KNN. Then final prediction calculated from predictions obtained each of algorithms by majority-based voting approach. So, this paper offers research on comparative analysis...
Static (DC) and dynamic (AC, at 14 MHz 8 GHz) magnetic susceptibilities of single crystals a ferromagnetic superconductor, EuFe2(As1-xPx)2 (x = 0.23), were measured in pristine state after different doses 2.5 MeV electron or 3.5 proton irradiation. The superconducting transition temperature, Tc(H), shows an extraordinarily large decrease. It starts Tc(H=0)≈24K the sample for both AC DC measurements, but moves to almost half that value moderate irradiation dose. Remarkably, not only Tc...
Temperature-dependent London penetration depth, $\ensuremath{\lambda}(T)$, of a high quality optimally doped ${\text{YBa}}_{2}{\text{Cu}}_{3}{\text{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ single crystal was measured using tunnel-diode resonator. Controlled artificial disorder induced at low temperature 20 K by 2.5 MeV electron irradiation with the accumulation large doses $3.8\ifmmode\times\else\texttimes\fi{}{10}^{19}$ and $5.3\ifmmode\times\else\texttimes\fi{}{10}^{19}$ electrons per...
Superconducting quantum circuits (SQC) are one of the most promising hardware platforms for computing, yet their performance is currently limited by presence various structural defects inside circuit's structure. Despite impressive progress in past decade, a precise understanding origin these from fabrication processes and impact on coherence still lacking. In this study, we performed comprehensive investigation microstructure, superconductivity, resonator quality factor Nb films deposited...
The effect of annealing on the superconducting properties niobium single crystals cut from same master boule was studied by local and global magnetic measurements, as well scanning tunneling microscopy (STM). formation large hydride precipitates observed in unannealed samples. variation structural after under high vacuum at 800 C, 1400 near melting point (2477 C) for a few seconds. initial samples had hydrogen content. Polarized optics magneto-optical studies show that is suppressed already...
London, $\lambda_L (T)$, and Campbell, $\lambda_{C} penetration depths were measured in single crystals of a topological superconductor candidate $\text{AuSn}_4$. At low temperatures, (T)$ is exponentially attenuated and, if fitted with the power law, $\lambda(T) \sim T^n$, gives exponents $n>4$, indistinguishable from isotropic $s-$wave gap Bardeen-Cooper-Schrieffer (BCS) asymptotic. The superfluid density fits perfectly entire temperature range to BCS theory. superconducting transition...