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Multistage RF filtering system for ultralow temperature nanoelectronic experiments
At ultralow temperatures (T< 100 mK) rather small external disturbance might lead to a noticeable overheating. While electron transport measurements the inevitable external EM noise, picked-up and transmitted through electric wires, results in a mismatch between the electron Te and the phonon Tphtemperatures P~W(Te^5-Tph^5), where P is the power dissipated at the sample with volume W. Hence, for sufficiently small nanoelectronic systems the effect might be clearly pronounced. Multiple methods have been suggested to reduce the undesired electron heating. Typically various RF filters are used to cut the impact of noisy EM environment. Often the supporting amplitude vs. frequency data are obtained only at room temperatures analyzing the impact of 'isolated' elements without taking into consideration the wires. Here we describe the custom made multistage RLC filtering system for ultralow temperature nanoelectronic experiments. The amplitude vs. frequency characteristics were measured down to very low temperatures. Distributed elements theory analysis supports experimental data.