Domain Expansion Readout For Magnetic Amplifying Magneto-Optical System

Abstract

Zero Field Magnetic Amplifying Magneto-optical System (ZF-MAMMOS) is realized by using an exchange-coupled tri-layer. The recorded mark with any length appears as the expanded domain with the size of collapse diameter in the readout layer without external magnetic field. As the ZF-MAMMOS has a resolution of 1/10 of a laser beam spot, this corresponds to 40 nm using a 405 nm laser diode and an objective lens of NA, 0.9. An AlSiN enhance/cooling layer was arranged for overwriting, and a GdFeCo recording assist layer was developed for high recording field sensitivity. As a result, the durability of overwriting is improved and the recording with ±140 Oe is achieved. This result also indicates that it is possible to realize a heat assisted magnetic recording with a very small recording field.

Ultrafast Laser Modulation of Local Magnetization Orientation in Perpendicularly Exchange-Coupled Bilayer

“…Typically, GdFeCo and TbFeCo can be used as the free and pinning layers, respectively, in perpendicular ECCs due to their dissimilar spin-orbit coupling and perpendicular magnetic anisotropy (PMA) [2,19]. RE-TM ECCs have attracted attentions also due to their applied potential in magnetic super resolution (MSR) for magnetooptical readout [20][21][22], but observation of the related dynamical process has not been reported.…”