Tord Claeson

A variable temperature scanning SQUID microscope

We present a design of a scanning SQUID microscope (SSM) operating in a temperature range between about 5 K (2 K with pumping) and 100 K.

Feasibility studies of ultra-small Josephson junctions for qubits

Most proposed realizations of a high temperature superconductor (HTS) qubit require the use of very small Josephson junctions. The properties of bicrystal junctions are especially interesting since they make it possible to implement several types of flux qubits in a relatively simple way. We have developed a technique that allows us to produce high quality sub-micrometer junctions in a reproducible way using bicrystal technology. We have successfully fabricated and characterized a large number of YBCO junctions and SQUIDs with bridge width as small as 0.2 micrometer on 0/spl deg/-3/spl deg/, 0/spl deg/-40/spl deg/ and 0/spl deg/-45/spl deg/ bicrystal STO substrates. The properties of these junctions have been extensively examined at temperatures down to 20 mK. The effects of external magnetic fields on these structures have been investigated. Figures of merit for the proposed qubits were also extracted from these measurements.

Low Dimensional Properties of Solids: Proceedings of the Nobel Jubilee Symposium

Nine Nobel laureates and some 40 other top researchers gathered for this symposium and this book contains the material presented in invited talks as well as the posters. The 34 papers are organized into three groups corresponding to various aspects of low dimensional physics of solids.