From micro- to nano-SQUIDs: applications to nanomagnetism

Due to a growing interest in quantum information processing based on spin systems, the micro-SQUID technique has been finding new interest and fabrication improvements have led to nano-SQUIDs. There are two types of nano-SQUIDs: either the cross section of the Josephson junctions is reduced to about 1 nm by using carbon nanotube junctions, or the loop size is reduced to a few 100 nm. This paper reviews the basic ideas of the micro-SQUID technique applied to magnetic nanostructures and shows that both types of nano-SQUIDs lead to a significant improvement concerning the detection of magnetization switching of individual magnetic particles or molecules.