Imaging and controlling vortex dynamics in mesoscopic superconductor–normal-metal–superconductor arrays

Abstract

Harnessing the properties of vortices in superconductors is crucial for fundamental science and technological applications; thus, it has been an ongoing goal to locally probe and control vortices. Here, we use a scanning probe technique that enables studies of vortex dynamics in superconducting systems by leveraging the resonant behavior of a raster-scanned, magnetic-tipped cantilever. This experimental setup allows us to image and control vortices, as well as extract key energy scales of the vortex interactions.Applying this technique to lattices of superconductor island arrays on a metal, we obtain a variety of striking spatial patterns that encode information about the energy landscape for vortices in the system. We interpret these patterns in terms of local vortex dynamics and extract the relative strengths of the characteristic energy scales in the system, such as the vortex-magnetic field and vortex-vortex interaction strengths, as well as the vortex chemical potential. We also demonstrate that the relative strengths of the interactions can be tuned and show how these interactions shift with an applied bias. The high degree of tunability and local nature of such vortex imaging and control not only enable new understanding of vortex interactions, but also have potential applications in more complex systems such as those relevant to quantum computing.

The peripheral vortex biome of confined quantum fluids and its influence on vortex dipole annihilation

“…The same initial conditions are applied, but now with the vortex healing length set by equation (8) and trap frequency set to…”

“…The ability to anticipate and control vortex dynamics in twodimensional, nonlinear quantum fluids is scientifically and technologically important to disciplines ranging from quantum turbulence [1] to the generation of non-Abelian anyons [2,3] and their use in topological quantum computing [4][5][6][7][8]. While the motion of individual vortices can now be predicted [9][10][11], it is often the nucleation and annihilation of oppositely charged vortex pairs (vortex dipoles) that dominates processes of interest [12].…”

Quantum Interference by Vortex Supercurrents

“…[ 1 ] Vortices are quantized excitations composed of supercurrents swirling around single‐flux lines piercing a “normal” region of the superconductor. These topological defects are stiff and extended in size [ 2–7 ] and affect the path and the phase evolution of coherent Cooper pairs (CPs). [ 8 ]…”

“…[1] Vortices are quantized excitations composed of supercurrents swirling around single-flux lines piercing a "normal" region of the superconductor. These topological defects are stiff and extended in size [2][3][4][5][6][7] and affect the path and the phase evolution of coherent Cooper pairs (CPs). [8] Measurements of magnetoresistance oscillations (MROs) are references to investigate vortex dynamics and their influence on the transport.…”

Local imaging of diamagnetism in proximity-coupled niobium nanoisland arrays on gold thin films

“…To explore this question, we used scanning Superconducting Quantum Interference Device microscopy (scanning SQUID microscopy or SSM) to measure the local diamagnetic response of arrays of niobium islands with proximity coupling via a thin layer of gold. Superconducting island arrays on normal metal can be a useful model for studying disorder in 2D superconductors, as both the disorder and critical current can be engineered by changing the spacing between superconducting islands [15][16][17].…”