SIGNIFICANT EVENTS - SCIENCE EVENTS
02/14/03

JPL Group Publishes Ideas on Observing Josephson Effects Near the Lambda Transition

The "Fluctuations of the Phase Difference across an Array of Josephson Junctions in Superfluid ⁴He near the Lambda Transition." by Talso Chui, Warren Holmes and Konstantin Penanen has been accepted for publication by the Physical Review Letters.

The Josephson effect, a quantum phenomenon, was largely formulated by the Nobel Prize Laureates Brian D. Josephson and Philip W. Anderson. This phenomenon in superconductors is the basis of the Superconducting QUantum Interference Device (SQUID). Using SQUIDs, researchers have made the most sensitive measurements of magnetic field, temperature, displacement and pressure. This paper is a theory of thermal noise in Josephson junctions, which is applied to the case of an array of superfluid helium weak links. We explain why the Josephson effect is observable in an array of weak links in superfluid ⁴He, and not in a single link. This theory is applicable to the design of ultra-sensitive gyroscopes for ground and space based applications.