Related papers: Transverse ratchet effect and superconducting vort…
The transverse (Hall) voltage in thin films of the high-temperature superconductor YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ with an artificial periodic pinning array is investigated. Columnar defect regions along the crystallographic $c$ axis, in…
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…
A dc voltage drop develops along amorphous indium oxide nanowires that are exposed to an ac bias source. This voltage is anti-symmetric with magnetic field and is characterized by sample specific quasi-periodic magneto-voltage oscillations.…
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 have designed, fabricated and tested a robust superconducting ratchet device based on topologically frustrated spin-ice nanomagnets. The device is made of a magnetic Co honeycomb array embedded in a superconducting Nb film. This device…
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 study the ratchet effect in a narrow pinning-free superconductive ring based on time-dependent Ginzburg-Landau (TDGL) equations. Voltage responses to external dc an ac currents at various magnetic fields are studied. Due to asymmetric…
We derive a refraction law for superconducting vortices at superconductor/normal metal interfaces. Simulations of the proximity effect under tilted geometries confirm this law and reveal vortex trapping for low effective mass. Under…
The controlled motion of objects through narrow channels is important in many fields. We have fabricated asymmetric weak-pinning channels in a superconducting thin-film strip for controlling the dynamics of vortices. The lack of pinning…
By spatially mapping the Doppler effect of an in-plane magnetic field on the quasiparticle tunneling spectrum, we have laterally imaged the vortex lattice in superconducting 2H-NbSe2. Cryomagnetic scanning tunneling spectroscopy was…
Experimental and theoretical studies on ratchet effects in graphene with a lateral superlattice excited by alternating electric fields of terahertz frequency range are presented. A lateral superlatice deposited on top of monolayer graphene…
We experimentally characterize the transverse vortex motion and observed some striking features. We found large structures and peaks in the Hall resistance, which can be attributed to the long-range inhomogeneous vortex flow present in some…
The work reported in my doctoral thesis is an experimental study of vortex dynamics and phase transitions in thin films of type II superconductors using scanning tunneling spectroscopy, low frequency ac susceptibility measurements and…
Superconducting films in contact with non-superconducting regular arrays can exhibit commensurability effects between the vortex lattice and the unit cell of the pinning array. These matching effects yield a slowdown of the vortex flow and…
A conformal pinning array can be created by conformally transforming a uniform triangular pinning lattice to produces a new structure in which the six-fold ordering of the original lattice is conserved but where there is a spatial gradient…
A controlled local enhancement of superconductivity yields unexpected modifications in the vortex dynamics. This local enhancement has been achieved by designing an array of superconducting Nb nanostructures embedded in a V superconducting…
Superconducting vortex loops have so far avoided experimental detection despite being the focus of much theoretical work. We here propose a method of creating controllable vortex loops in the superconducting condensate arising in a normal…
A serious obstacle that impedes the application of low and high temperature superconductor (SC) devices is the presence of trapped flux. Flux lines or vortices are induced by fields as small as the Earth's magnetic field. Once present,…
Driven vortex lattices have been studied in a material with strong pinning, such as Nb films. Samples in which natural random pinning coexists with artificial ordered arrays of defects (submicrometric Ni dots) have been fabricated with…
We analyze magnetic textures in a thin magnetic film and screening currents induced by these textures in a superconducting film. The films are supposed to be parallel and close to each other, but interact only via magnetic fields. We…