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Using Lorentz microscopy to directly image vortices, we investigate vortex motion control and rectification in a niobium superconductor. We directly observe a net motion of vortices along microfabricated channels with a spatially asymmetric potential, even though the vortices were driven by an oscillatory field. By observing the individual motion of vortices, we clarify elementary processes involved in this rectification. To further demonstrate the ability to control the motion of vortices, we created a tiny vortex "racetrack" to monitor the motion of vortices in a closed circuit channel.
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http://dx.doi.org/10.1103/PhysRevLett.95.087002 | DOI Listing |
Materials (Basel)
August 2025
Photovoltaic Technologies Laboratory, Department of Physics, Faculty of Fundamental Sciences, Vilnius Gediminas Technical University (Vilnius Tech), Saulėtekio av. 3, LT-10257 Vilnius, Lithuania.
The transport properties of biased type II superconductors are strongly influenced by external magnetic fields, which play a crucial role in optimizing the stability and performance of low-noise superconducting electronic devices. A major challenge is the stochastic behavior of Abrikosov vortices, which emerge in the mixed state and lead to energy dissipation through their nucleation, motion, and annihilation. Uncontrolled vortex dynamics can introduce electronic noise in low-power systems and trigger thermal breakdown in high-power applications.
View Article and Find Full Text PDFNat Commun
August 2025
School of Civil Engineering, The University of Sydney, Sydney, NSW, Australia.
As collections of grains flow, free-surface deformations often develop. These typically suggest the presence of secondary flows, smaller in magnitude than the primary motion but driving complex three-dimensional internal structures. While one can infer such behaviour from boundaries or simulations, we have not previously been able to directly observe secondary flows experimentally.
View Article and Find Full Text PDFBull Math Biol
August 2025
Department of Mathematics, University of Arizona, 1200 E University Blvd, Tucson, 85721, AZ, USA.
This work presents a three-dimensional fully-coupled fluid-structure interaction (FSI) model of a pulsing soft coral polyp where the movement of the tentacles is driven by a prescribed active tension during contraction with a passive expansion due to the elastic behavior of the tentacles. The resulting motion of the tentacles is emergent rather than prescribed. This approach allows one to determine how the coral's underlying morphology, mechanics, and neural activation affect its kinematics and the resulting fluid motion, which has implications for soft robotic design.
View Article and Find Full Text PDFThe rotational Doppler effect (RDE) of structured light carrying orbital angular momentum (OAM) has attracted widespread interest in optical sensors and OAM spectrum detection. However, the motion parameters of spinning objects are the main focus of the RDE-based research, and other equally significant attitude properties have rarely been considered. In the experiments, we noticed an intriguing phenomenon: the rotational Doppler spectral distribution is affected by both the ellipticity of the elliptical optical vortex (EOV) and the tilt angle between the rotational axis and the optical axis.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
July 2025
We theoretically construct vectorial optical fields (VOFs) embedded with off-axis polarization singularities (PSs) using autofocusing Airy beams as orthogonal components. The focal intensity profiles of the composite VOFs and propagation dynamics of the embedded PSs are investigated. Our study reveals that isolated, simple, low-order PSs maintain their topological morphologies while undergoing rotational motion during propagation, whereas high-order PSs or low-order PSs resulting from the superposition of high-order optical vortices (OVs) split into stable, low-order PS-coupled configurations due to the spin-orbit interaction (SOI).
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