Researchers at NIST and Johns Hopkins University have discovered a new phenomenon called zero field switching (ZFS) that could revolutionize memory and computing devices. The team found they could flip the magnetization of a nanometer-thick CoFeB magnet between 0 and 1 states using only electric current through adjacent Pt and W metal layers, without needing a magnetic field.
The ZFS effect was achieved by creating a spin current, where electrons with aligned spins move perpendicular to the current direction. This spin-orbit torque (SOT) exerts a torque on the CoFeB layer, flipping its magnetization. The device consists of Pt, W, and CoFeB layers sandwiched between gold electrodes on a silicon surface.
This breakthrough could lead to smaller, lower-power memory devices that don’t require magnetic fields for switching. The research team is now investigating other materials for ZFS and studying how the effect changes with smaller nanomagnets.
Source: https://www.nist.gov/materials/zero-field-switching-zfs-effect-nanomagnetic-device
Keywords: Spin current, Spin-orbit torque, Magneto-optical Kerr effect
