Technology
Spintronics & MRAM
Magnetoresistive RAM and spintronic devices that use electron spin for non-volatile memory and ultra-efficient computing.
8 companies
Explainer
Spintronics & MRAM explained
Spintronics uses the spin of electrons, a quantum property that acts like a tiny magnet, as well as their charge to store and process information. The best-known product is MRAM, magnetoresistive random-access memory.
An MRAM cell holds a bit in the magnetic orientation of a thin layer. Two magnetic layers sit either side of an insulating barrier, and the electrical resistance is higher or lower depending on whether the layers point the same way or opposite ways. This effect, called tunnel magnetoresistance, is how the bit is read. A related effect, giant magnetoresistance, earned the 2007 Nobel Prize in Physics for Albert Fert and Peter Grünberg.
How it differs from the usual approach
DRAM and SRAM lose their data when power is removed, and flash wears out after many writes and is slow to write. MRAM keeps data without power, writes quickly and survives a very large number of write cycles. Its drawbacks are lower density and higher cost per bit than DRAM and flash, so it fills niches rather than replacing them. Spin-based logic and neuromorphic devices are still research topics.
Where it is used
- Embedded non-volatile memory in microcontrollers, replacing embedded flash.
- Industrial, automotive and aerospace systems that need reliable memory.
- Caches and buffers in storage systems that must survive power loss.
- Hard-drive read heads, which use magnetoresistance.
- Research on spin-based logic and low-power AI.
What to watch
- Foundries offer embedded STT-MRAM at nodes around 28 nm and 22 nm, where embedded flash is hard to scale. This has been the main route into volume products.
- Spin-orbit torque MRAM is a research direction aiming at faster and more efficient writing.
- MRAM is not expected to displace DRAM in the near term because of density and cost.
- Magnetic devices are being studied as synapses and random-number sources for AI hardware.
Frequently asked questions
What is spintronics?
Spintronics is electronics that uses the spin of electrons, as well as their charge, to carry information. Its main commercial product is MRAM memory.
What is MRAM good for?
MRAM keeps its data without power, writes quickly and handles many rewrites. That makes it useful in embedded and industrial systems, though it costs more per bit than DRAM or flash.
Will MRAM replace DRAM or flash?
Not soon. Its density and cost are behind those technologies. It is used where its other properties justify the price.
- NUNumem Numem is a Sunnyvale, California company that develops memory based on MRAM, or magnetoresistive random access memory, which stores bits in magnetic states so data persists without power and leaks little energy when idle. Its NuRAM product is pitched as an alternative to SRAM, the fast on-chip memory that uses power even when idle, and its SmartMem subsystem is intended to manage several memory types. It announced a Series A round in September 2023 from Cambium Capital and Doorga Capital. Memory & Storage · Spintronics & MRAM Series A, Sep 2023
- CTCrocus Technology Crocus Technology made integrated magnetic field sensors based on tunnel magnetoresistance, or TMR, an effect where electrical resistance changes sharply with magnetic field. Products included magnetic switches, latches and angle sensors for automotive, consumer, industrial and medical uses. The company began with magnetic memory technology developed at the Spintec laboratory in Grenoble, France, in 2004. Allegro MicroSystems completed its acquisition of Crocus on October 31, 2023, for 420 million US dollars in cash. Spintronics & MRAM —
- Antaios Antaios develops SOT-MRAM, a magnetic memory that stores bits using electron spin and keeps its contents without power. Spin-orbit torque (SOT) writes data by sending current along a separate path next to the magnetic cell, which is intended to give fast, durable switching suited to embedded memory and AI workloads. The record describes it as a spinout of Spintec, a French research laboratory in Grenoble, and lists Grenoble as its base with a 2017 founding. Its website could not be reached, so these details and its current status are unconfirmed. Spintronics & MRAM · Memory & Storage —
- Avalanche Technology Avalanche Technology, based in Fremont, California, designs and sells MRAM, a memory that stores data in magnetic states and so keeps it without power. Its parts use spin-transfer torque, where a current flips the magnetic direction of a cell, built on 300mm standard CMOS processes. The main product line is Persistent SRAM, offered in densities from 1Mb to 16Mb, which behaves like fast SRAM but does not lose data at power-off. The company was founded in 2006 and was formerly known as Yadav Technology. Its founder and CEO is Petro Estakhri, and it has signed manufacturing agreements with Sony and UMC. In-Memory Computing · Spintronics & MRAM · Memory & Storage $168.4M
- SMSpin Memory Spin Memory develops SOT-MRAM, a type of magnetic memory that stores bits using the spin of electrons rather than electric charge. Spin-orbit torque (SOT) writes data by passing current along a separate path beside the magnetic cell, which is intended to allow fast switching and longer endurance than earlier magnetic designs. Magnetic memory keeps its contents without power and can serve as embedded cache. The company is listed in Fremont, California and 2011 as its founding year. Neither detail, nor its current products and status, could be confirmed from a primary source during checking. Spintronics & MRAM · Memory & Storage —
- TCTDK Corporation TDK Corporation is a Japanese maker of electronic components, power supplies and sensors, and it also does research in spintronics, which uses electron spin to store and process information. It has described a spin-memristor, a magnetic device whose resistance changes with its history, as a building block for neuromorphic computing, which imitates how brain cells work. TDK was founded in 1935 to make ferrite magnetic material, is headquartered in Tokyo, and is listed on the Tokyo Stock Exchange. Spintronics & MRAM · Neuromorphic Computing —
- Everspin Technologies Everspin Technologies makes discrete magnetoresistive RAM, or MRAM, in Toggle and spin-transfer torque forms. MRAM stores data in magnetic states rather than electric charge, so it keeps its contents without power while approaching the speed of SRAM. The company also licenses embedded MRAM technology and offers backend foundry services, and it works with GlobalFoundries on embedded MRAM. Everspin was spun out of Freescale Semiconductor in 2008, is based in Chandler, Arizona, and has traded on Nasdaq under MRAM since its 2016 IPO. Spintronics & MRAM · In-Memory Computing · Memory & Storage —
- NCNVE Corporation NVE Corporation develops devices based on spintronics, which uses the magnetic spin of electrons rather than charge alone. Its products include spintronic magnetic sensors, signal isolators that pass data across an electrical barrier, and MRAM memory chips, sold mainly to industrial, medical and other embedded customers. The company is based in Eden Prairie, Minnesota, and is publicly listed. Its magnetic sensors and isolators are used where small size and low power draw matter. Spintronics & MRAM · Memory & Storage —