Using a phenomenological approach based on the fluctuation-dissipation theorem we calculate suppression of superconducting currents due to phase fluctuations and find that, in contrast to a recent prediction, the effect of thermal fluctuations cannot account for linear temperature dependence of the superfluid density in high-T(c) superconductors at low temperatures. Quantum fluctuations are found to dominate over thermal fluctuations at low temperatures. Near T(c) sizable thermal fluctuations are found to suppress the critical current in the stack direction stronger than in the direction along the layers. The spectral density of voltage fluctuations at small frequencies is nonzero, in contrast to what may be expected from a naive interpretation of the Nyquist formula.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.86.708 | DOI Listing |
J Mol Model
January 2025
Shanxi Jiangyang Chemical Limited Company, Taiyuan, 030041, Shanxi, China.
Context: DNAN/DNB cocrystals, as a newly developed type of energetic material, possess superior safety and thermal stability, making them a suitable alternative to traditional melt-cast explosives. Nonetheless, an exploration of the thermal degradation dynamics of the said cocrystal composite has heretofore remained uncharted. Consequently, we engaged the ReaxFF/lg force field modality to delve into the thermal dissociation processes of the DNAN/DNB cocrystal assembly across a spectrum of temperatures, encompassing 2500, 2750, 3000, 3250, and 3500 K.
View Article and Find Full Text PDFInsect Sci
January 2025
EDYSAN, Ecologie et Dynamique des Systèmes Anthropisés, UMR 7058 CNRS, Université de Picardie Jules Verne, Amiens, France.
Polyphagous insect species develop using multiple host plants. Often considered beneficial, polyphagy can also be costly as host nutritional quality may vary. Drosophila suzukii (Matsumura) is an invasive species that can develop on numerous fruit species over the annual cycle.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Institute of Materials Engineering, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
The ubiquitous nature of thermal fluctuations poses a limitation on the identification of crystal structures. However, the trajectory of an atom carries a fingerprint of its surroundings. This rationalizes the search for a method that can determine the local atomic configuration via the analysis of the movement of an individual atom.
View Article and Find Full Text PDFOptical clocks require an ultra-stable laser to probe and precisely measure the frequency of the narrow-linewidth clock transition. We introduce a portable ultraviolet (UV) laser system for use in an aluminum quantum logic clock, demonstrating a fractional frequency instability of approximately mod = 2 × 10. The system is based on an ultra-stable cavity with crystalline AlGaAs/GaAs mirror coatings, with a frequency quadrupling system employing two single-pass second-harmonic generation (SHG) stages.
View Article and Find Full Text PDFThe optical permittivity of monocrystalline direct bandgap semiconductors can be described well by critical point models based on parabolic band approximation (CPPB). However, the optical permittivity of polycrystalline direct bandgap semiconductors like halide perovskite thin films requires a more precise description. Till now, only thermal bandgap fluctuation or exponential decay of density of states is incorporated into the CPPB model.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!