Local thermometry technique based on proximity-coupled superconductor/normal-metal/superconductor devices

In mesoscopic superconductor/normal-metal/superconductor (SNS) heterostructures, it is known that the resistance of the normal metal between the superconductors has a strong temperature dependence. Based on this phenomenon, we have developed a new type of thermometer, which dramatically enhances our ability to measure the local electron temperature Te at low temperatures. Using this technique, we have been able to measure small temperature gradients across a micron-size sample, opening up the possibility of quantitatively measuring the thermal properties of mesoscopic devices.