Atomic steps guide quantum vortices

Short answer

A research centre in Japan has shown that atom-high steps on the surface of a thin superconductor force the quantum vortices inside it to flow in a particular direction. This guiding effect can be tuned using temperature and magnetic field. The finding is a piece of basic materials science that could eventually contribute to lower-power, more stable superconducting hardware.

Highlights

Scientists at Japan's Research Center for Materials Nanoarchitectonics (MANA) found that atomic steps on a thin superconductor force vortices to flow in a set direction.
At intermediate magnetic fields, vortices moved more than 1,000 times more easily along the steps than across them.
The findings were published in Physical Review B on July 30; the guiding effect can be tuned by changing temperature or magnetic field.

Close-up view of an electronic circuit board showing a microchip and its connections — Photo: Ivan Chumak / Pexels

28 September 20261 min readEditor-in-chief: Uğur Deniz İlhan

A team at Japan's Research Center for Materials Nanoarchitectonics (MANA), part of the National Institute for Materials Science (NIMS), has found a new way to guide the quantum vortices inside superconductors. According to the institute's press release, the team, led by Takashi Uchihashi, studied an ultrathin superconductor with regularly arranged atomic steps on its surface.

Why do vortices move more easily along the steps?

Superconducting vortices are tiny quantum objects that directly affect how a superconductor behaves, so controlling their direction of motion matters for developing low-power superconducting technologies. The team used scanning tunnelling microscopy to confirm the parallel steps and directly image vortices sitting along them. Four-terminal resistance measurements showed that at intermediate magnetic fields, vortices moved more than 1,000 times more easily along the steps than across them. Uchihashi said the atomic-scale steps act as effective rails that guide vortices, and that this guiding effect can be tuned simply by changing the temperature or magnetic field. The findings were published in Physical Review B on July 30.

Why does this finding matter?

The team says atom-high surface steps could act as effective rails for guiding vortex motion and heat flow, opening possibilities for controlling future superconducting technologies. Basic materials research like this is directly tied to the push for lower-power, more stable components as quantum hardware moves toward commercialisation.