A long-term study has been conducted at CNRS/LPN in order to fill the gap of high performance FETs (Field-Effect Transistors) for high impedance, low-power and low-frequency deep cryogenic readout electronics, and to meet the needs of various experiments from astrophysics to mesoscopic physics. Significant progress has been accomplished: the CNRS/LPN is now capable to realize ultra-low noise cryo-HEMTs (High Electron Mobility Transistors) working at low frequencies and low temperature from 77 K down to 4.2K, even lower. We can offer specific cryo-HEMTs according to the needs of various experiments.
The cryo-HEMTs, with an input capacitance of 92 pF and a power consumption of 100 µW at 4.2 K, show an equivalent input noise voltage of 6 nV/√Hz @ 1 Hz and a noise current of 20 aA/√Hz @ 1 Hz, and a white noise voltage as low as 0.2 nV/√Hz [Appl. Phys. Lett. 105, 13504 (2014)]. These cryo-HEMTs have been selected for the ionization readout by the SuperCDMS and Edelweiss-III experiments for the cryogenic Dark Matter search. Sixty nine test cryo-HEMTs were supplied for these two experiments.
The cryo-HEMTs, with an input capacitance of about 3.5 pF and a power consumption of 100 µW at 4.2 K, show equivalent input noise voltage and noise current at 4.2 K of 1 nV/√Hz and 0.1 fA/√Hz @ 1 kHz, respectively; and a white noise voltage of about 0.2 nV/√Hz. These cryo-HEMTs allowed us to realize high performance deep cryogenic readout electronics and to perform new experiments in mesoscopic physics, e.g., the quantum limit of heat flow across a single electronic channel [Science 342, 601 (2013)] and Hong-Ou-Mandel experiment for temporal investigation of single-electron fractionalization [Nature Commun. 6, 7854 (2015)].
In addition to applications in academic laboratories, our cryo-HEMTs are also used by a German company, Stahl Electronics, to realize cryogenic readout electronics for various scientific instruments.