PHEMT as a circuit element for high impedance nanopower amplifiers for ultra-low temperatures application

•We measure the HEMT characteristics at temperature of 50 mK for the first time.•To characterize the HEMT, the relative parameters are proposed to use.•We show high-impedance HEMT amplifiers are able to consume <100 nW power.

In this work, high electron mobility transistor (HEMT) was studied as a circuit element for amplifiers operating at temperatures of the order of 10–100 mK. To characterize the HEMT, the relative parameters are proposed to be used. HEMT characteristics were measured at a temperature of 50 mK for the first time. It follows from the reported studies that the power consumption of high-impedance HEMT-based amplifiers can be reduced down to hundreds of nanowatt or even lower.