We investigate the ground state of the irrationally frustrated Josephson junction array with a controlling anisotropy parameter λ that is the ratio of the longitudinal Josephson coupling to the transverse one. We find that the ground state has one-dimensional periodicity whose reciprocal lattice vector depends on λ and is incommensurate with the substrate lattice. Approaching the isotropic point λ=1, the so-called hull function of the ground state exhibits analyticity breaking similar to the Aubry transition in the Frenkel-Kontorova model. We find a scaling law for the harmonic spectrum of the hull functions, which suggests the existence of a characteristic length scale diverging at the isotropic point. This critical behavior is directly connected to the jamming transition previously observed in the current-voltage characteristics by a numerical simulation. On top of the ground state there is a gapless continuous band of metastable states, which exhibit the same critical behavior as the ground state. © 2012 American Physical Society.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUK-I1-005-04
Acknowledgements: This work was supported by a Grant-in-Aid for Scientific Research (C) (Grant No. 21540386), a Grant-in-Aid for Scientific Research on Priority Areas “Novel States of Matter Induced by Frustration”(Grant No. 1905200*), and King Abdullah University of Science and Technology Global Research Partnership (Grant No. KUK-I1-005-04).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.