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Quantum phase transition in superconducting Au0.7In0.3 films of very low normal-state sheet resistance

M. M. Rosario·H. Wang·Yu. Zadorozhny·Y. Liu
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Abstract

We report the observation of a quantum phase transition (QPT), tuned by a parallel magnetic field, between a superconducting and metallic state in Au0.7In0.3 films of very low normal-state sheet resistance (< 90 Ohms). These films can be modeled as a random array of superconductor-normal metal-superconductor (SNS) junctions. Electrical transport and tunneling measurements suggest that, in the metallic state, the film consists of superconducting In-rich grains not linked by Josephson coupling. Whether phase fluctuation, which is not expected to be strong in such an SNS junction system according to the phase-number uncertainty relation, or a different physical process drives the observed QPT is discussed.

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M. M. Rosario, H. Wang, Yu. Zadorozhny, Y. Liu. 2003-07-25. Quantum phase transition in superconducting Au0.7In0.3 films of very low normal-state sheet resistance. https://arxiv.org/abs/cond-mat/0307629

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