Related papers: Upper frequency limits for vortex guiding and ratc…
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…
We have measured the frequency and temperature dependences of complex ac conductivity, \sigma(\omega)=\sigma_1(\omega)-i\sigma_2(\omega), of NbN films in zero magnetic field between 0.1 to 10 GHz using a microwave broadband technique. In…
Tantalum (Ta) based superconducting circuits have been demonstrated to enable record qubit coherence times and quality factors, motivating a careful study of the microscopic origin of the remaining losses that limit their performance. We…
We study the magnetic response of superconducting $\gamma$-Ga via low temperature scanning tunneling microscopy and spectroscopy. The magnetic vortex cores rely substantially on the Ga geometry, and exhibit an unexpectedly-large axial…
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…
Excess conductance fluctuations with peculiar temperature-dependence from 1.4 to 250 K were observed in curved nano-graphite sheets with an electrode gap length of 300 and 450 nm, whereas the conductance fluctuation is greatly suppressed…
Spin vortices in magnetic nanopillars are used as GHz oscillators, with frequency however essentially fixed in fabrication. We demonstrate a model system of a two-vortex nanopillar, in which the resonance frequency can be changed by an…
We have measured periodic oscillations of rectified dc voltage versus magnetic field V_{dc}(B) in a superconducting aluminum thin-film circular-asymmetric figure-of-eight microstructure threaded by a magnetic flux and biased with a…
In type-I superconductors, zero electrical resistivity and perfect diamagnetism define two fundamental criteria for superconducting behavior. In contrast, type-II superconductors exhibit more complex mixed state physics, where magnetic flux…
We present a study of the anisotropic vortex parameters as obtained from measurements of the microwave complex resistivity in the vortex state with a tilted applied magnetic field in YBa2Cu3O7-x thin films with BaZrO3 nanorods. We present…
Ferromagnet/superconductor heterostructures allow for the combination of unique physical phenomena offered by the both fields of magnetism and superconductivity. It was shown recently that spin waves can be efficiently scattered in such…
Vortex dynamics in a multiband anisotropic superconducting such as the Fe based superconductors, is interesting and potentially important for applications. In this study we examine flux-creep data for fields along the second magnetization…
We investigate the effect of the anisotropy and of the directional pinning in YBa$_2$Cu$_3$O$_{7-x}$ films grown by pulsed laser ablation from targets containing BaZrO$_3$ at 5% mol. BaZrO$_3$ inclusions self-assemble to give nanorods…
Top-gated graphene transistors operating at high frequencies (GHz) have been fabricated and their characteristics analyzed. The measured intrinsic current gain shows an ideal 1/f frequency dependence, indicating an FET-like behavior for…
Multiband superconductors support the excitation of vortices with fractional quantum flux, known as fractional vortices. In the ground state, the fractional vortices in different bands bond together to form a composite vortex with the…
We observed mode-locking (ML) of rf-dc driven vortex arrays in a superconducting weak pinning a-NbGe film. The ML voltage shows the expected scaling $V\propto f\sqrt{B}$ with $f$ the rf-frequency and $B$ the magnetic field. For large…
This study conducts a comprehensive investigation into the reversal mechanism of magnetic vortex cores in a nanopillar system composed of two coupled ferromagnetic dots under zero magnetic field conditions. The research employs a…
We report the free flux flow (FFF) resistivity associated with a purely viscous motion of the vortices in moderately clean d-wave superconductor Bi:2201 in the strongly overdoped regime (T_c=16K) for a wide range of the magnetic field in…
Resistance in superconductors arises from the motion of vortices driven by flowing supercurrents or external electromagnetic fields and may be strongly affected by thermal or quantum fluctuations. The common expectation borne out in…
We present ellipsometric measurements of the far-infrared dielectric response of polycrystalline samples of the new pnictide superconductor RO0.82F0.18FeAs (R=Nd and Sm). We find evidence that the electronic properties are strongly…