Nanomagnet Arrays for Information Storage

The past decade has witnessed a thousand-fold increase in magnetic recording areal density, which has revolutionized the way information is stored and retrieved. These advances are the first demonstration of spintronics, which utilizes electron spin, as well as its charge, for information storage, transmission and manipulation. The societal impacts are exemplified by the Nobel Prize in Physics awarded a few months ago to the discovery of the Giant Magnetoresistance (GMR) effect that opened the door to spintronics. As noted by the Nobel committee, the use of GMR can also be regarded “as one of the first major applications of nanotechnology”. Extending from this exciting path, the current project aims at realizing prototype ultrahigh density and data-rate patterned magnetic recording media and memory made of arrays of nanomagnets. Such media will have more than one order of magnitude increase in both storage density and data rate. The success of the project will lead to a new technology in achieving magnetic recording at 1 Terabit/in2 and beyond, enabling numerous new applications.

The project will coordinate two UC research groups with complementary capabilities to develop nanomagnet arrays for information technology applications in future generation ultrahigh density and datarate patterned magnetic recording media and memory. Macroscopic as well as ordered arrays of deep sub-100nm nanomagnets will be made by nanotemplating and e-beam lithography method, respectively. Magnetization reversal mechanisms at such reduced dimensions will be investigated using magnetometry and a novel first-order reversal curve method, in both quasi-static and dynamic regimes. Intrinsic properties of single nanomagnets will be studied using cavity-enhanced magneto-optical Kerr spectroscopy, and compared with the collective responses of the arrays. These studies will allow us to design and realize optimal nanomagnet arrays with controlled ultrafast precessional switching schemes for information storage.