Nanoscale control over single vortex motion in an unconventional superconductor

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Information Science

Background:

• Precise control of superconducting vortices is essential for understanding vortex dynamics and braiding.
• Existing methods for vortex manipulation have limitations in dense vortex lattices.

Purpose of the Study:

• To introduce a novel scanning tunneling microscope (STM) based method for manipulating vortex lines in the layered superconductor FeSe.
• To enable tunable vortex pinning and controlled deformation of vortex lines at the nanoscale.

Main Methods:

• Utilizing a scanning tunneling microscope (STM) tip to establish weak contact with the FeSe surface.
• Locally reducing the superconducting gap to create tunable vortex pinning potentials.
• Employing analytical modeling to understand the deformation mechanics.

Main Results:

• Demonstrated controlled deformation of vortex lines within dense vortex lattices in FeSe.
• Identified that the deformation strength depends logarithmically on conductance and tip geometry.
• Established local strain-induced gap suppression as the mechanism for STM-mediated vortex manipulation.

Conclusions:

• The proposed STM method offers precise, nanoscale control over superconducting vortices.
• Findings provide fundamental insights into vortex behavior relevant for quantum information applications.
• This technique facilitates advanced studies of vortex dynamics and braiding.