Nanomagnet's Spin Damping Observed for First Time
Among the core components of any modern computer is the high speed, volatile RAM, but in the future a new kind of memory may be used based on the spin of electrons. Such spintronic memory has many advantages over modern electronic memory, including the ability to store data without power. A key property of a component in spintronic memory has finally been measured by the NIST, after researchers developed a new kind of microscope, just for the task.
Nanomagnets are extremely small magnets which would be responsible for storing data within spintronic memory, but exist at an awkward size; too big for atomic physics tools to observe but too small for more conventional instruments. To solve this problem the researchers had to construct a new microscope specifically for measuring the spin relaxation or damping of the nanomagnets. This microscope works by shining two green lasers on the nanomagnet, which interfere with each other to create a microwave signal. This signal excites the spin waves and the polarization of one of the lasers is then used to observe the pattern of spin excitation. By measuring this as a function of the nanomagnet's magnetic field and the frequency of microwaves, the researchers were able to get the information they were looking for.
Measurements like this could lead to spintronic memory units that can operate at less energy than currently possible. The reason for this is that the smaller the damping, the less energy is required to flip a bit within the memory.