The study of non-shield head for perpendicular recording

Summary form only given. With the current shield type head applied to higher areal density recording, the gap length (shield to shield separation) decreases. We estimated the gap length necessary for higher areal densities and it became less than 20 nm for 400-500 Gbpsi. Thus it will be difficult to use current GMR or TMR elements. However J.G. Zhu (2001) proposed a GMR design without an anti-ferromagnetic layer, while we investigate another way, i.e. a non-shield head or yoke structure for perpendicular recording with ultra-high areal density.