Samani, Mohammad and Scheller, Christian and Sedeh, Omid Sharifi and Zumbühl, Dominik and Yurttagül, Nikolai and Grigoras, Kestutis and Gunnarsson, David and Prunnila, Mika and Jones, Alexander and Prance, Jonathan and Haley, Richard (2022) Microkelvin electronics on a pulse-tube cryostat with a gate Coulomb-blockade thermometer. Physical Review Research, 4 (3): 033225. ISSN 2643-1564
Full text not available from this repository.Abstract
Temperatures below 1 mK on-chip hold great potential for quantum physics but present a great challenge due to the lack of suitable thermometry and the detrimental pulse-tube vibrations of cryogen-free refrigerators. Here, we solve the pulse-tube problem using a rigidly wired metallic sample holder, which provides a microkelvin environment with low heat leaks despite the vibrations. Further, we demonstrate an improved type of temperature sensor, the gate Coulomb blockade thermometer (gCBT), employing a gate metallization covering the entire device. This immunizes against nanofabrication imperfections and uncontrollable offset charges, and extends the range to lower temperatures compared to a junction CBT with the same island capacitance, here down to ≈ 160 μ K for a 10% accuracy. Using on- and off-chip cooling, we demonstrate electronic temperatures as low as 224 ± 7 μ K, remaining below 300 μ K for 27 hours, thus providing time for experiments. Finally, we give an outlook for cooling below 50 μ K for a future generation of microkelvin transport experiments.