A new storage element suitable for large-sized memory arrays — The twistor

Abstract

Three methods have been developed for storing information in a coincident-current manner on magnetic wire. The resulting memory cells have been collectively named the “twistor”. Two of these methods utilize the strain sensitivity of magnetic materials and are related to the century old Wertheim or Wiedemann effects; the third utilizes the favorable geometry of a wire. The effect of an applied torsion on a magnetic wire is to shift the preferred direction of magnetization into a helical path inclined at an angle of 45° with respect to the axis. The coincidence of a circular and a longitudinal magnetic field inserts information into this wire in the form of a polarized helical magnetization. In addition, the magnetic wire itself may be used as a sensing means with a resultant favorable increase in available signal since the lines of flux wrap the magnetic wire many times. Equations concerning the switching performance of a twistor are derived An experimental transistor-driven, 320-bit twistor array has been built. The possibility of applying weaving techniques to future arrays makes the twistor approach appear economically attractive.