Superconducting and normal state properties of Niobium nanofilms have been systematically investigated as a function of film thickness, on different substrates. The width of the superconducting-to-normal transition for all films is remarkably narrow, confirming their high quality. The superconducting critical current density exhibits a pronounced maximum for thickness around 25 nm, marking the 3D-to-2D crossover. The magnetic penetration depth shows a sizeable enhancement for the thinnest films. Additional amplification effects of the superconducting properties have been obtained with sapphire substrates or squeezing the lateral size of the nanofilms. For thickness close to 20 nm we measured a doubled perpendicular critical magnetic field compared to its large thickness value, indicating shortening of the correlation length and the formation of small Cooper pairs. Our data analysis indicates an exciting interplay between quantum-size and proximity effects together with strong-coupling effects and the importance of disorder in the thinnest films, placing these nanofilms close to the BCS-BEC crossover regime.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5856833 | PMC |
| http://dx.doi.org/10.1038/s41598-018-22983-6 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Exploring van der Waals Cuprate Superconductors Using a Hybrid Microwave Circuit.
Nano Lett
January 2025
Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
The advent of two-dimensional van der Waals materials is a frontier of condensed matter physics and quantum devices. However, characterizing such materials remains challenging due to the limitations of bulk material techniques, necessitating the development of specialized methods. Here, we investigate the superconducting properties of BiSrCaCuO flakes by integrating them with a hybrid superconducting microwave resonator.
View Article and Find Full Text PDFUltrahigh-Power Carbon-Based Supercapacitors through Order-Disorder Balance.
Small
January 2025
Institute of Smart City and Intelligent Transportation, Southwest Jiaotong University, Chengdu, 610031, China.
Although carbon-based supercapacitors (SCs) hold the advantages of high-power and large-current characteristics, they are difficult to realize ultrahigh-power density (> 200 kW kg) and maintain almost constant energy density at ultrahigh power. This limitation is mainly due to the difficulty in balancing the structural order related to the electrical conductivity of carbon materials and the structural disorder related to the pore structure. Herein, we design a novel super-structured tubular carbon (SSTC) with a crosslinked porous conductive network to solve the structure order-disorder tradeoff effect in carbon materials.
View Article and Find Full Text PDFAtomically thin high-entropy oxides via naked metal ion self-assembly for proton exchange membrane electrolysis.
Nat Commun
January 2025
School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
Designing efficient Ruthenium-based catalysts as practical anodes is of critical importance in proton exchange membrane water electrolysis. Here, we develop a self-assembly technique to synthesize 1 nm-thick rutile-structured high-entropy oxides (RuIrFeCoCrO) from naked metal ions assembly and oxidation at air-molten salt interface. The RuIrFeCoCrO requires an overpotential of 185 mV at 10 m A cm and maintains the high activity for over 1000 h in an acidic electrolyte via the adsorption evolution mechanism.
View Article and Find Full Text PDFGenetic Algorithm-Enhanced Direct Method in Protein Crystallography.
Molecules
January 2025
Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
Direct methods based on iterative projection algorithms can determine protein crystal structures directly from X-ray diffraction data without prior structural information. However, traditional direct methods often converge to local minima during electron density iteration, leading to reconstruction failure. Here, we present an enhanced direct method incorporating genetic algorithms for electron density modification in real space.
View Article and Find Full Text PDFOptimization of In-Situ Growth of Superconducting Al/InAs Hybrid Systems on GaAs for the Development of Quantum Electronic Circuits.
Materials (Basel)
January 2025
CNR-IOM-Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, 34149 Trieste, Italy.
Hybrid systems consisting of highly transparent channels of low-dimensional semiconductors between superconducting elements allow the formation of quantum electronic circuits. Therefore, they are among the novel material platforms that could pave the way for scalable quantum computation. To this aim, InAs two-dimensional electron gases are among the ideal semiconductor systems due to their vanishing Schottky barrier; however, their exploitation is limited by the unavailability of commercial lattice-matched substrates.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!