Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 49: Superconductivity: Superconducting Electronics I

TT 49.9: Vortrag

Mittwoch, 14. März 2018, 12:00–12:15, H 2053

Development of a novel calorimetry setup based on metallic paramagnetic temperature sensors — •Andreas Reifenberger, Matthew Herbst, Sebastian Kempf, Andreas Fleischmann, and Christian Enss — Kirchhoff-Institut für Physik, Universität Heidelberg, INF 227, D-69120 Heidelberg

For the measurement of the specific heat of superconducting mg-sized metallic glass samples in the temperature range down to 10 mK we have developed a new microfabricated platform. It addresses challenging aspects of setups of this kind such as the thermal contact between sample and platform, the necessary thermometer resolution, and an addenda heat capacity exceeding that of the samples of interest (typically nJ/K at 20 mK). Our setup allows us to use the relaxation method, where the thermal relaxation following a well defined heat pulse is monitored to extract the specific heat. The sample platform (5 × 5  mm²) includes a microstructured paramagnetic Ag:Er temperature sensor, which is read out by a dc-SQUID via a superconducting pickup loop. In this way, a relative temperature precision of 30 nK/√Hz can be reached, while the addenda heat capacity falls well below 0.5 nJ/K for T < 300 mK. A gold-coated mounting area (4.4 × 3   mm²) is included to improve the thermal contact between sample and platform. The performance of our setup is presented and discussed.