Related papers: Phase Transition and Critical Dynamics in Diluted …
We consider dissipative quantum phase transitions in Josephson junction arrays and show that the disordered phase in this extended system can be viewed as an unusual floating phase in which the states of local $(0+1)$-dimensional elements…
The dynamics of thermally excited vortices in a dilute two-dimensional Josephson junction array where a fraction of the superconducting islands is missing has been investigated using a multiple trapping model. An expression for the…
Phase transitions give crucial insight into many-body systems, as crossovers between different regimes of order are determined by the underlying dynamics. These dynamics, in turn, are often constrained by dimensionality and geometry. For…
We have investigated the dynamics of underdamped Josephson junctions. In addition to the usual crossover between macroscopic quantum tunnelling and thermally activated (TA) behaviour we observe in our samples with relatively small Josephson…
Resistance of a Josephson junction array consisting of randomly distributed lead (Pb) islands on exfoliated single layer graphene shows a broad superconducting transition to zero with an onset temperature close to the transition temperature…
We investigate the nature of the phase transition occurring in a planar XY-model spin system with dipole-dipole interactions. It is demonstrated that a Berezinskii-Kosterlitz-Thouless (BKT) type of phase transition always takes place at a…
In this work we study by numerical methods the phase dynamics in ballistic graphene-based short Josephson junctions. The supercurrent through a graphene junction shows a non-sinusoidal phase-dependence, unlike a conventional junction ruled…
We investigate dynamic transitions and stochastic resonance phenomena in two-dimensional fully frustrated Josephson-junction arrays driven by staggered oscillating magnetic fields. As the temperature is lowered, the dynamic order parameter,…
We studied the commensurate semi-fluxon oscillations of Josephson flux-flow (JFF) in a Bi-2212 stacked structures near $T_c$ as a probe of melting of Josephson vortex lattice (JVL). We found that oscillations exist above 0.5T. The amplitude…
Using large scale quantum Monte Carlo simulations of lattice bosonic models, we precisely investigate the effect of weak Josephson tunneling between 2D superfluid or superconducting layers. In the clean case, the Kosterlitz-Thouless…
Weakly coupled superconducting layers are described by the three-dimensional XY model with strong coupling in two directions and weak coupling in the third direction. For the usual Josephson-type interplane coupling the coherence between…
The properties of vortices in Josephson junction arrays are investigated in the quantum regime near the superconductor-insulator transition. We derive and study an effective action for vortex dynamics that is valid in the region where the…
The Josephson effect is a kind of macroscopic quantum phenomenon that supercurrent flows through a Josephson junction without any voltage applied. We predict a novel vortex-state-mediated Josephson effect in an SNS Josephson junction…
We have studied experimentally the magnetic field-induced superconductor-insulator quantum phase transition in one-dimensional arrays of small Josephson junctions. The zero bias resistance was found to display a drastic change upon…
We have investigated the dynamics of vortices in a dilute two dimensional Josephson junction array where a fraction of the superconducting islands is missing. We have used the multiple trapping model to calculate the mobility of vortices…
The scaling behavior of the current-voltage ($IV$) characteristics of a two-dimensional proximity-coupled Josephson junction array (JJA) with quenched bond disorder was investigated for frustrations $f=1/5$, 1/3, 2/5, and 1/2. For all these…
A critical value in the product of the anisotropy parameter and the magnetic field is observed in interlayer Josephson-vortex systems by extensive Monte Carlo simulations. Below/above this critical value the thermodynamic phase transition…
We study persistent currents in a Josephson junction array wrapped around a cylinder. The $T=0$ quantum statistical mechanics of the array is equivalent to the statistical mechanics of a classical $xy$ spin system in 2+1 dimensions at the…
We study the decoupling transition of flux lattices in a layered superconductors at which the Josephson coupling J is renormalized to zero. We identify the order parameter and related correlations; the latter are shown to decay as a power…
We study the dynamics of vortices in strongly disordered $d=2$ Josephson junction arrays and superconducting films driven by a current. We find a dynamic phase transition in vortex flow at a current $I_p>I_c$. Below $I_p$ there is plastic…