Giant fluctuations of superconducting order parameter in ferromagnet-superconductor single-electron transistors

• Spin dependent transport in a ferromagnet-superconductor single-electron transistor is studied theoretically taking into account spin accumulation, spin relaxation, gap suppression, and charging effects. A strong dependence of the gap on the magnetic state of the electrodes is found, which gives rise to a magnetoresistance of up to 100%. We predict that fluctuations of the spin accumulation can play such an important role as to cause the island to fluctuate between the superconducting and normal states. Furthermore, the device exhibits a nearly complete gate-controlled spin-valve effect.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

double tunnel-junctions

spin imbalance

critical field

injection

transport

Publication and Content Type

ref (subject category)

art (subject category)