The emergence of spin electronics in data storage

Abstract

Electrons have a charge and a spin, but until recently these were considered separately. In classical electronics, charges are moved by electric fields to transmit information and are stored in a capacitor to save it. In magnetic recording, magnetic fields have been used to read or write the information stored on the magnetization, which 'measures' the local orientation of spins in ferromagnets. The picture started to change in 1988, when the discovery of giant magnetoresistance opened the way to efficient control of charge transport through magnetization. The recent expansion of hard-disk recording owes much to this development. We are starting to see a new paradigm where magnetization dynamics and charge currents act on each other in nanostructured artificial materials. Ultimately, 'spin currents' could even replace charge currents for the transfer and treatment of information, allowing faster, low-energy operations: spin electronics is on its way.

Ferroelectric control of spin-transfer torque in multiferroic tunnel junctions

“…Information storage has experienced a tremendous growth owning to advancements in the field of spintronics 1 . In particular, magnetic tunnel junctions (MTJs), consisting of two ferromagnetic metal layers separated by a thin insulating barrier layer, are the leading devices for field sensing, non-volatile magnetic random access memories (MRAMs), and spin logic applications [2][3][4] .…”

Spin injection at remanence into III-V spin light-emitting diodes using (Co/Pt) ferromagnetic injectors

“…1,2 In the field of semiconductors, spintronics becomes an alternative solution to standard electronics technology, which it is known will reach physical limitations in the near future. 3 This explains the large amount of work on spintronics with hybrid metal/semiconductor heterostructures for the past ten years, once it was proposed to solve the problem of impedance mismatch 4 by the use of an interface resistance, typically a tunneling barrier.…”

Identifying the character of ferromagnetic Mn in epitaxial Fe/(Ga,Mn)As heterostructures

“…A promising direction that goes beyond conventional methodologies is to tailor novel properties by exploiting interface effects in highly controlled heterostructures ͑HS͒, as extensively demonstrated in oxide-based materials. [7][8][9] Following this approach, recent experimental efforts aimed at tuning specific magnetic properties in FM metal/DMS-based interfaces. In the case of direct exchangecoupled HS, the investigation of spin valve effect in MnAs/ ͑Ga,Mn͒As at low temperature ͑4.2 K͒ found the apparent formation of a inhomogeneous magnetic spring in the ͑Ga,Mn͒As region 10 and a decrease in exchange coupling after insertion of a spacer layer ͓MnAs/ p-GaAs/ ͑Ga, Mn͒As͔.…”