相关论文: Rocking ratchets in 2D Josephson networks: collect…
We study numerically the directed motion of vortices (antivortices) under an applied ac bias in two-dimensional Josephson junction arrays (JJA) with an asymmetrically modulated periodic vortex pinning potential. We find that the ratchet…
By means of electrical transport measurements we have studied the rectified motion of vortices in ratchet potentials engineered on over-damped Josephson junction arrays. The rectified voltage as a function of the vortex density shows a…
The vortex ratchet effect has been studied in Al films patterned with square arrays of submicron antidots. We have investigated the transport properties of two sets of samples: (i) asymmetrical antidots where vortices are driven by an…
We study the transport of vortices excited by an ac current in an Al film with an array of nanoengineered asymmetric antidots. The vortex response to the ac current is investigated by detailed measurements of the voltage output as a…
We investigate experimentally a deterministic underdamped Josephson vortex ratchet -- a fluxon-particle moving along a Josephson junction in an asymmetric periodic potential. By applying a sinusoidal driving current one can compel the…
We simulate vortices in superconductors interacting with two-dimensional arrays of triangular traps. We find that, upon application of an ac drive, a net dc flow can occur which shows current reversals with increasing ac drive amplitude for…
We study the dynamics of vortices in an asymmetric ring channel driven by an external current I in a Corbino setup. The asymmetric potential can rectify the motion of vortices and cause a net flow without any unbiased external drive, which…
We present theoretical and numerical investigations of vortices driven by strong dc and ac currents in long Josephson junctions described by a nonlinear integro-differential equation which takes into account nonlocal electrodynamics of…
We demonstrate using computer simulations that the simplest vortex ratchet system for type-II superconductors with artificial pinning arrays, an asymmetric one-dimensional (1D) potential array, exhibits the same features as more complicated…
We experimentally demonstrate that the origin of multiply reversed rectified vortex motion in an asymmetric pinning landscape is a consequence not only of the vortex-vortex interactions but also essentially depends on the ratio between the…
The mixed-state resistive response of a superconductor thin film with an asymmetric washboard pinning potential subject to superimposed dc and ac currents of arbitrary amplitudes and frequency at finite temperature is theoretically…
Two-dimensional arrays of ballistic Josephson junctions are important as model systems for synthetic quantum materials. Here, we investigate arrays of multiterminal junctions which exhibit a phase difference $\varphi_0$ at zero current.…
A conformal transformation of a uniform triangular pinning array produces a structure called a conformal crystal which preserves the six-fold ordering of the original lattice but contains a gradient in the pinning density. Here we use…
We propose and study a novel way to produce a DC transport of vortices when applying an AC electrical current to a sample. Specifically, we study superconductors with a graduated random pinning density, which transports interacting vortices…
We present a review of our numerical studies on non equilibrium vortex dynamics in Josephson Junction arrays (JJA) driven by a dc current. Dynamical phase diagrams for different magnetic fields, current directions and varying temperature…
A collective mechanism for current reversal in superconducting vortex ratchets is proposed. The mechanism is based on a two-dimensional instability of the ground state (T=0) of the system. We illustrate our results with numerical…
We report on the influence a preferential magnetic vortices motion has on the magnitude of the inverse ac Josephson effect (the appearance of dc current Shapiro steps) and the coherent operation of asymmetrical parallel arrays of YBaCuO…
Competition between the vortex lattice and a lattice of asymmetric artificial defects is shown to play a crucial role in ratchet experiments in superconducting films. We present a novel and collective mechanism for current reversal based on…
We study numerically the motion of vortices in two-dimensional arrays of resistively shunted Josephson junctions. An extra vortex is created in the ground states by introducing novel boundary conditions and made mobile by applying external…
We have numerically and analytically studied ac+dc driven Josephson-junction arrays with a single vortex or with a single vortex-antivortex pair present. We find single-vortex steps in the voltage versus current characteristics (I-V) of the…