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Experimental evidence for a collective insulating state in two-dimensional superconductors

G. Sambandamurthy·L. W. Engel·A. Johansson·E. Peled·D. Shahar
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Abstract

We present the results of an experimental study of the current-voltage characteristics in strong magnetic field ($B$) of disordered, superconducting, thin-films of amorphous Indium-Oxide. As the $B$ strength is increased superconductivity degrades, until a critical field ($B_c$) where the system is forced into an insulating state. We show that the differential conductance measured in the insulating phase vanishes abruptly below a well-defined temperature, resulting in a clear threshold for conduction. Our results indicate that a new collective state emerges in two-dimensional superconductors at high $B$.

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G. Sambandamurthy, L. W. Engel, A. Johansson, E. Peled, D. Shahar. 2005-01-14. Experimental evidence for a collective insulating state in two-dimensional superconductors. https://doi.org/10.1103/physrevlett.94.017003

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