1. A ferroelectric field effect transistor (FET) exhibiting hysteresis, comprising: a semiconductor substrate of a first conductivity type; a source, said source comprising a region of said semiconductor substrate doped to have a conductivity opposite that of said semiconductor substrate; a drain, spaced from said source, said drain comprising a portion of said semiconductor substrate doped to have a conductivity opposite of said substrate, a channel being formed in the space between said source and said drain; a ferroelectric layer overlaying the channel; a conductive electrode layer overlaying the ferroelectric layer; wherein charge is injected into and removed from the ferroelectric layer, the quantity of charge so stored being selected so as to provide the ferroelectric FET with a first threshold voltage when charge is stored and a second threshold voltage when charge is removed.