title: Transition by breaking of analyticity in the ground state of Josephson junction arrays as a static signature of the vortex jamming transition.
abstract: 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.
authors.affiliation: Department of Applied Physics, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. nogawa@serow.t.u-tokyo.ac.jp
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Nogawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Yoshino
authors.forename: Bongsoo
authors.initials: B
authors.lastname: Kim