Is There a Lower Size Limit for Superconductivity?
| العنوان: | Is There a Lower Size Limit for Superconductivity? |
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| المؤلفون: | Subhrangsu Sarkar, Nilesh Kulkarni, Pushan Ayyub, Krishnamohan Thekkepat, Ruta Kulkarni, Umesh V. Waghmare |
| المصدر: | Nano Letters. 17:7027-7032 |
| بيانات النشر: | American Chemical Society (ACS), 2017. |
| سنة النشر: | 2017 |
| مصطلحات موضوعية: | Superconductivity, Materials science, Condensed matter physics, Phonon, Mechanical Engineering, Bioengineering, 02 engineering and technology, General Chemistry, Surface phonon, Electron, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Nanocrystalline material, Ab initio quantum chemistry methods, 0103 physical sciences, General Materials Science, Density functional theory, 010306 general physics, 0210 nano-technology, Quantum |
| الوصف: | The ultimate lower size limit for superconducting order to exist is set by the “Anderson criterion”—arising from quantum confinement—that appears to be remarkably accurate and universal. We show that carefully grown, phase-pure, nanocrystalline bcc-Ta remains superconducting (with ordering temperature, TC ≈ 0.9 K) down to sizes 40% below the conventional estimate of the Anderson limit of 4.0 nm. Further, both the TC and the critical magnetic field exhibit an unusual, nonmonotonic size dependence, which we explain in terms of a complex interplay of quantum size effects, surface phonon softening, and lattice expansion. A quantitative estimation of TC within first-principles density functional theory shows that even a moderate lattice expansion allows superconductivity in Ta to persist down to sizes much lower than the conventional Anderson limit, which can be traced to anomalous softening of a phonon due to its coupling with electrons. This appears to indicate the possibility of bypassing the Anderson crite... |
| تدمد: | 1530-6992 1530-6984 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c2dca0738e1ec497cb6d1b8c36baa3cc https://doi.org/10.1021/acs.nanolett.7b03659 |
| رقم الأكسشن: | edsair.doi.dedup.....c2dca0738e1ec497cb6d1b8c36baa3cc |
| قاعدة البيانات: | OpenAIRE |
Find this issue from the American Chemical Society | تدمد: | 15306992 15306984 |
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