Low-Temperature Electronics

Considering potential practical applications of low-temperature phenomena, a general survey is made of the temperature dependence of noise and electrical resistance down to the region of Absolute Zero. It is shown that the signal-to-noise ratio in a metallic resistor can be increased by lowering its temperature, while cooling has little effect on carbon resistors. The theory of electrical conductance in metals is reviewed, and it is determined that whenever ohmic losses are important as in an inductance, decreasing the temperature can be a help. The phenomenon of superconductivity is treated, including use of the superconducting properties of certain metals in the construction of a very sensitive bolometer and in the frictionless suspension of a lead sphere.