The transient build-up and phase synchronization of thin magnetic film parametrons

THE DEVELOPMENT of thin magnetic film parametrons (also termed parametric phase-locked subharmonic oscillators) has been stimulated by their potential as low-cost reliable logic elements for medium- and low-speed computing machines.^1–4 Among the many ways to implement the parametron, the best known consists of a single-domain uniaxial magnetic film coupled to a coil whose axis is directed along the hard magnetization direction of the film; the coil is further shunted by a tuning capacitor to form a tank circuit resonating at the subharmonic frequency. A second winding, orthogonal to the signal coil, produces a bias field and a pump field along the easy direction of the film.¹ The oscillation characteristics and phase bi-stability of this device have been verified.