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Experimental Study of Positionally Disordered Josephson Junctions Arrays

Young-Je Yun·In-Cheol Baek·Mu-Yong Choi
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Abstract

We experimentally studied the effect of positional disorder on a Josephson junction array with $f = n$, ${1/2} + n$, or ${2/5} + n$ flux quanta per unit cell for integral $n$. This system provides an experimental realization of a two-dimensional XY model with random phase shifts. Contrary to many earlier numerical and analytical investigations, our results suggest that low-temperature superconductivity is never destroyed by positional disorder. As the disorder strength increased, the Kosterltz-Thouless (KT) type order in the $f = 0$ and 1/2 systems changed to a non-KT type order with a long-range phase coherence, which persisted even in the maximal disorder limit. A possible finite-temperature glass transition is discussed.

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Young-Je Yun, In-Cheol Baek, Mu-Yong Choi. 2005-09-06. Experimental Study of Positionally Disordered Josephson Junctions Arrays. https://doi.org/10.1209/epl%2Fi2006-10258-6

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