DARPA eyes altermagnetic devices that control magnetics for enhanced radar and communications
Key Highlights
Questions and answers:
- What is the main focus of DARPA’s new Altered B project? It seeks industry input on altermagnetic devices that could revolutionize electronics and computing by enabling energy-efficient spin control without net magnetization.
- How do altermagnetic materials differ from traditional magnetic materials? Unlike ferromagnets and antiferromagnets, altermagnets allow for stable spin-polarized currents without producing a macroscopic magnetic field, thanks to their unique crystal lattice structure and spin alignment.
- What are some potential defense and aerospace applications of altermagnetic devices? Applications include magnetic propulsion, radiation shielding, stealth technologies, energy storage, quantum sensing, advanced radar and communications, and electronics for hypersonic and autonomous vehicles.
ARLINGTON, Va. – U.S. military researchers are asking industry for new ideas in altermagnetic devices that could produce dramatic improvements in applications like data storage; energy efficiency; artificial intelligence (AI); and materials sciences.
Officials of the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., have issued a request for information (DARPA-SS-26-01) for the Altermagnetism for devices (Altered B) project.
Altermagnetic devices could reshape electronics, computing, and communications because they can control magnetics without net magnetization and energy-efficient spin manipulation.
These devices capitalize on a newly discovered form of magnetism called altermagnetism that bridges the gap between ferromagnetism and antiferromagnetism.
Spinning atoms
Altermagnetic materials differ from conventional magnets because the magnetic moments of their atoms not only align in opposite directions, but also rotate in the crystal lattice to enable stable spin-polarized electronic currents without producing a macroscopic magnetic field. This subtle rotation of magnetic structure enables precision control of electron spin -- a key requirement for spintronic device development.
Altermagnetic devices promise ultrafast, low-power, and environmentally sustainable operation in several kinds of enabling technologies considered crucial for future aerospace and defense applications, experts say.
They offer the speed of ferromagnets and the stability of antiferromagnets to enable a thousand-fold increase in memory and processor speed while eliminating interference from stray magnetic fields.
Their ability to control spin without an external field can help design electronics that consume far less energy and generate less heat than do conventional magnets.
Tell me more about aerospace and defense applications of altermagnetic devices ...
- Altermagnetic devices have potential aerospace and defense applications in magnetic propulsion systems; active magnetic shields for radiation protection; electromagnetic interference (EMI) suppression; magnetic field-based sensors and actuators; enhanced energy storage and conversion; advanced radar and communications; advanced weapon systems; quantum sensing and navigation; hypersonic technologies; and autonomous and swarming vehicles. Altermagnetic devices could lead to maglev-based propulsion systems for aircraft or spacecraft; space propulsion; solar radiation shielding; stealth aircraft; magnetic capacitors to store and release electricity rapidly; multi-frequency radar and communications; electromagnetic weapons; sensitive measurements of gravitational anomalies for anti-submarine warfare (ASW) and navigation in deep space; thermal management in hypersonic weapons; and communications among swarming uncrewed vehicles.
Altermagnetic devices also could underpin ultra-low-power AI chips, cryptographic accelerators, and radiation-resistant electronics suitable for space or battlefield use.
Altermagnetism, like antiferromagnetism, aligns the spins in an altermagnetic system in a collinear, antiparallel fashion to yield zero net magnetization. Unlike antiferromagnetism, however, the crystal fields of the altermagnet antialigned spins are related by a rotational symmetry element, rather than a translational or inversion element.
Spintronic devices benefit from the interaction of spin-polarized currents with magnetic materials to perform computations and store data, with the promise that switching energies potentially could be orders of magnitude lower than current metal–oxide–semiconductor field-effect transistor (MOSFET) technologies.
Technological challenges
Integrating ferromagnetic or antiferromagnetic materials into spintronic devices, however, presents challenges.
Ferromagnetic materials exhibit unacceptably long switching times, and their non-zero net magnetization raises concerns about interference of fringing fields with other integrated circuit elements.
Antiferromagnetic materials do not exhibit spin splitting in their band structures and therefore do not naturally support device-level manipulation of spin polarization. Altermagnets might sidestep the kinds of problems ferromagnets and antiferromagnets face when designing spintronic devices because of their spin-split band structures and zero net magnetization.
Power-efficient computers
The promise of ultralow energy computation finally might be within reach if the design of future spintronic devices takes advantage of altermagnets’ properties.
Still, isn't clear how to use altermagnetic materials to build a device. Several device-switching proposals remain experimentally untested. DARPA researchers are asking industry for ideas on the future directions for designing and building practical electronic and spintronic devices that capitalize on altermagnetism.
Companies interested should email nine-page white papers no later than 12 Nov. 2025 to DARPA at [email protected]. Email questions or concerns to [email protected]. More information is online at https://sam.gov/workspace/contract/opp/4fd49ead4efb48938f69069e5316fd88/view.