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The Defense Intelligence Agency's Defense Warning Office issued this Defense Intelligence Reference Document, dated 23 March 2010, as one of a series of advanced technology reports produced in FY 2009 under its Advanced Aerospace Weapon System Applications Program. The report reviews metallic spintronics, including giant magnetoresistance, spin-transfer-torque and antiferromagnetic spintronics, along with their applications. It concludes that spintronic devices could offer radiation-resistant, low-power electronics suited to aerospace use and long space trips.
From the source: Release of 2026-09-18 Incident: 3/23/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys metallic spintronics, a branch of electronics that seeks to use both the electric charge and the magnetic spin of electrons to store, detect, and manipulate information, and argues that the field could lead to faster, lower-power, and more radiation-resistant devices than conventional semiconductor electronics. The report focuses on two main effects: giant magnetoresistance (GMR), which allows magnetic states to be read through changes in electrical resistance, and spin-transfer torque (STT), which allows electrical currents to change those magnetic states. The DIRD reviews their underlying physics, the experimental work then available, and possible applications in memory, sensors, oscillators, and logic devices. The document treats metallic spintronics as a promising field while emphasizing that many of its more advanced proposed applications still require substantial further development.
UNCLASSIFIED//FOR OFFIEJIAI:: WSE 0Ptl::1f Contents 1. Introduction ......................................................................................................iv 2. Giant Magnetoresistance .................................................................................... 1 2.1 GMR Basics .........................................................................................1••········· 1 2.2 GMR Applications ........................................................................................ 3 3. Spin-Transfer-Torque ......................................................................................... 4 3.1 STT Basics ........................................................................................,........... 4 3.2 STT Experiments .................................................................................. ............. 7 3.3 STT Applications ............................................................................ ..... ........... 10 3.4 STT-Driven Motion of Magnetic Domain Walls ........................................... 12 4, Antiferromagnetic Metal Spintronics ............................................................... 12 4.1 Antiferromagnetic GMR .........,............ .,............................................ ........... 13 4.2 Antiferromagnetic STT....................................................................... ........ 14 5. Summary and Conclusions ............................................................................... 16 6. References ..............................................................................................,......... 18 Figures Figure 1. In a Magnetic Multilayer, Several Atomic Layers of Magnetic Material Alternate With Layers of Nonmagnetic Material ...................................... 1 Figure 2. Resistance of a Magnetic Multilayer R Versus Magnetic Field ...... ............ 2 Figure 3. Differential Resistance dV/dI of a Mechanical Point Contact as a Function of Current for a Series of Magnetic Fields................................................ 4 Figure 4. Device Schematics for STT Experiments ................................................. 5 Figure 5. Qualitative Picture of STT ....................................................................... 6 Figure 6. Torques on a Magnetic Moment in a Magnetic Field and Subject to an Electrical Current........................................................................., 1••••••••••• 7 Figure 7. Spin-Torque-Driven Magnetic Switching .................................................. 8 Figure 8. Oscillatory Voltage .................................................................................. 9 Figure 9. Scanning Transmission X-ray Microscopy Images ................................. 10 Figure 10. Conventional MRAM Cell ....................................................................... 11 Figure 11. Racetrack Memory Concept .................................................................. 12 Figure 12. Schematic of Point Contact to Sample Geometry ................................. 15 iii UNCLASSIFIED/ /FOA 8FFIGIAI:: WSE OPtl::lf
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 27 pages are in the text index: search them above, or from the library's search.