相关论文: 3-junction SQUID rocking ratchet
We analyzed voltage rectification for dc SQUIDs biased with ac current with zero mean value. We demonstrate that the reflection symmetry in the 2-dimensional SQUID potential is broken by an applied flux and with appropriate asymmetries in…
We argue that the phase across an asymmetric dc SQUID threaded by a magnetic flux can experience an effective ratchet (periodic and asymmetric) potential. Under an external ac current, a rocking ratchet mechanism operates whereby one sign…
We study transport in an asymmetric SQUID which is composed of a loop with three capacitively and resistively shunted Josephson junctions: two in series in one arm and the remaining one in the other arm. The loop is threaded by an external…
We study theoretically the efficiency of an asymmetric superconducting quantum interference device (SQUID) which is constructed as a loop with three capacitively and resistively shunted Josephson junctions. Two junctions are placed in…
We study diffusion of the Josephson phase in the asymmetric SQUID subjected to a time-periodic current and pierced by an external magnetic flux. We analyze a relation between phase diffusion and quality of transport characterized by the dc…
Motivated by a recent experimental progress in realizing Majorana fermions (MFs) in a heterostructure of a spin-orbit coupling nanowire and superconductor (V. Mourik et al., Science.1222360), we investigate a SQUID formed by the novel…
We investigate experimentally a Josephson vortex ratchet -- a fluxon in an asymmetric periodic potential driven by a deterministic force with zero time average. The highly asymmetric periodic potential is created in an underdamped annular…
Operation of a Superconducting Quantum Interference Device (SQUID) made of stacked Josephson junctions is analyzed numerically for a variety of junction parameters. Due to a magnetic coupling of junctions in the stack, such a SQUID has…
Using a focused He$^+$ beam for nanopatterning and writing of Josephson barriers we fabricated specially shaped Josephson junctions of in-line geometry in YBa$_2$Cu$_3$O$_7$ thin film microbridges with an asymmetry ratio of critical…
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 introduce a three-junction SQUID that can be effectively used as an optimal tunable element in Josephson quantum computing applications. This device can replace the simple dc SQUID generally used as tunable element in this kind of…
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…
We present an experimental study of the magnetic flux dependence of the critical current of a balanced SQUID with three Josephson junctions in parallel. Unlike for ordinary dc SQUIDs, the suppression of the critical current does not depend…
It is now well established that a Josephson junction made from conventional spin-singlet superconductors containing ferromagnetic layers can carry spin-triplet supercurrent under certain conditions. The first experimental signature of that…
We have fabricated and studied a new kind of DC SQUID in which the magnitude and sign of the critical current of the individual Josephson junctions can be controlled by additional voltage probes connected to the junctions. We show that the…
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…
We study diffusion in ratchet systems. As a particular experimental realization we consider an asymmetric SQUID subjected to an external ac current and a constant magnetic flux. We analyze mean-square displacement of the Josephson phase and…
We present a theoretical study on the dynamical properties of three-dimensional arrays of Josephson junctions. Our results indicate that such superconducting networks represent highly sensitive 3D-SQUIDs having some major advantages in…
We demonstrate experimentally the operation of a deterministic Josephson ratchet with tunable asymmetry. The ratchet is based on a $\varphi$ Josephson junction with a ferromagnetic barrier operating in the underdamped regime. The system is…
We experimentally investigate the stochastic phase dynamics of planar Josephson junctions (JJs) and superconducting quantum interference devices (SQUIDs) defined in epitaxial InAs/Al heterostructures, and characterized by a large ratio of…