Cryotron

A cryotron is a controlled active resistance that uses in its work the phenomenon of the dependence of the temperature at which superconductivity occurs on the magnitude of the magnetic field.

The advantages of the cryotron are small dimensions and very low control power. The disadvantages of the cryotron are the need for deep cooling and relatively low output power. A cryotron consists of a superconducting rod (for example, tantalum ) placed in a vessel with liquid helium and surrounded by a control wire (for example, niobium ). By changing the current in the control winding, it is possible to change the magnetic field strength and transfer the conductive rod from the superconducting state to the normal one and vice versa, thus changing its resistance in a non-linear manner ^[1] .