Superconducting strip could become an ultra-low-voltage sensor

Apr 30, 2012

Researchers studying a superconducting strip observed an intermittent motion of magnetic flux which carries vortices inside the regularly spaced weak conducting regions carved into the superconducting material. These vortices resulted in alternating static phases with zero voltage and dynamic phases, which are characterised by non-zero voltage peaks in the superconductor. This study, which is about to be published in EPJ B¹, was carried out by scientists from the Condensed Matter Theory Group of the University of Antwerp, Belgium, working in collaboration with Brazilian colleagues.

Superconductors, when subjected to sufficiently strong magnetic fields, feature vortices that carry quantized amounts of , although the natural tendency of is to expel such flux. The authors relied on the Ginzburg-Landau theory to study the dynamic of the nanometric- to millimetric-scale-width superconducting strip, which was subjected to a applied at a right angle and a current applied alongside its length.

Typically, weakly acting superconducting regions are natural impediments for the passage of electrical current. However, the authors found that they also work as efficient pathways for vortices to enter and exit the superconducting strip. The increasing magnetic field also increases the density of mutually repelling vortices, which stimulates vortex motion across the strip in the presence of an external current. At the same time, the barrier for vortex entry and exit on the strip boundaries is also dependent on the magnetic field. This interplay of magnetic-field-dependent barriers and vortex-vortex interaction results in an on/off vortex motion in increasing magnetic fields.

Due to the simple geometry of the strip, these results can be confirmed experimentally in magnetoresistance measurements. These findings could be applicable in gate devices used to control various modes of on/off states in electrical systems which operate in specific windows of temperature, applied magnetic field, current and voltage.

Explore further: IHEP in China has ambitions for Higgs factory

More information: European Physical Journal B (EPJ B), DOI: 10.1140/epjb/e2012-30013-7

Related Stories

Stripes offer clues to superconductivity

May 17, 2010

New images of iron-based superconductors are providing telltale clues to the origin of superconductivity in a class of ceramic materials known as pnictides. The images reveal that electrons responsible for ...

Tiny superconductors withstand stronger magnetic fields

Feb 04, 2005

Ultrathin superconducting wires can withstand stronger magnetic fields than larger wires made from the same material, researchers now report. This finding may be useful for technologies that employ superconducting ...

Recommended for you

IHEP in China has ambitions for Higgs factory

3 hours ago

Who will lay claim to having the world's largest particle smasher?. Could China become the collider capital of the world? Questions tease answers, following a news story in Nature on Tuesday. Proposals for ...

The physics of lead guitar playing

5 hours ago

String bends, tapping, vibrato and whammy bars are all techniques that add to the distinctiveness of a lead guitarist's sound, whether it's Clapton, Hendrix, or BB King.

The birth of topological spintronics

6 hours ago

The discovery of a new material combination that could lead to a more efficient approach to computer memory and logic will be described in the journal Nature on July 24, 2014. The research, led by Penn S ...

The electric slide dance of DNA knots

9 hours ago

DNA has the nasty habit of getting tangled and forming knots. Scientists study these knots to understand their function and learn how to disentangle them (e.g. useful for gene sequencing techniques). Cristian ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) Apr 30, 2012
Similar to the vortices that appear in superfluid helium when the superfluid is stressed. The vortices are the sink into which the "super" material (superconductor or superfluid)sloughs off the stress.