Sub-100 mK cooling using normal-metal¿insulator¿superconductor tunnel junctions
Peter J. Lowell, Galen C. O'Neil, Jason M. Underwood, Xiaohang NMN Zhang, Joel N. Ullom
Normal-metal∖insulator∖superconductor (NIS) junctions can be used as solid-state refrigerators since the hottest electrons preferentially tunnel from the normal metal into the superconductor. In this paper, we present NIS junctions optimized to cool electrons from a bath temperature of 100 mK. We measure a temperature reduction of the electrons in the refrigerator junctions from 100 to 26 mK which agrees with device models. Independent measurements of the electron temperature using thermometer junctions measure a temperature decrease from 100 to 48 mK. Theories explaining the difference in measured temperatures are discussed.
, O'Neil, G.
, Underwood, J.
, , X.
and Ullom, J.
Sub-100 mK cooling using normal-metal¿insulator¿superconductor tunnel junctions, Journal of Low Temperature Physics, [online], https://doi.org/10.1007/s10909-013-1009-0
(Accessed November 30, 2023)