1. Evidence for enhanced phase fluctuations in nanostructured niobium thin films.
- Author
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Ting-Hui Chen, Hsiang-Hsi Kung, Chang-Ran Wang, Chia-Tso Hsieh, and Wei-Li Lee
- Subjects
- *
FLUCTUATIONS (Physics) , *NIOBIUM , *THIN films - Abstract
In a superconducting nanostructure, phase fluctuations are prominent and give rise to finite resistance below superconducting transition temperature Tc. By using a monolayer polymer/nanosphere hybrid we developed previously, we fabricated a large array of interconnected niobium (Nb) honeycomb lattices with the thinnest interconnected linewidth d ranging from 36 nm to 89 nm. The honeycomb cells form a highly ordered triangular lattice with more than 108 unit cells extending over few mm² area, which enables the detailed transport study at nanometer scales. We found Tc gradually drops with decreasing d due to the phase-slip effect, while the critical field at lower temperature tends to follow that of a continuous Nb thin film. One likely scenario is to consider a model system of numerous superconducting islands interconnected by short phase-slip junctions, where the phase coherence is dictated by the phase slippage in the nanoconstriction. This was strongly supported by the excellent fitting to the thermally activated phase-slip model and also the unusual phenomena of transition width narrowing in high fields. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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