  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.
