High-efficiency single-turn write head for high-speed recording

A write element for a magnetoresistive ("MR") head or a giant magnetoresistive (GMR) head includes a yoke and a coil. The coil made of a microstrip transmission line. The coil is a single turn and is U-shaped. The yoke of the write element includes laminated bottom pole, and top pole which are made of thin layers of ferromagnetic material antiferromagnetically exchange coupled to each other through a very thin nonmagnetic metallic layer. The yoke is made of metallic superlattices exhibiting strong antiferromagnetic exchange coupling between ferromagnetic layers through thin nonmagnetic metallic layers. The coil and the yoke are intertwined to provide two or more flux interactions between them. The yoke has a symmetrical structure with three interconnect vias, thereby reducing the effective magnetic length of the yoke. The antiferromagnetically exchange-coupled yoke has a stable single domain structure that exhibits very high switching time and does not suffer from hysteresis losses.