Through magnetic nanodots. As the article covers, this advancement is in RAM.
From the link:
Using magnetic nanodots in the vortex state, researchers have designed a new kind of non-volatile memory that could offer increased speed and density for next-generation non-volatile random access memories (RAM). The new design takes advantage of magnetic vortices’ ability to store binary information as positive or negative core polarities, which can be controlled by simply changing the frequency of the rotating vortex cores of the nanodots.
The new technique, called frequency-controlled magnetic vortex memory, was developed by a team of researchers, B. Pigeau, et al., from France, Germany, and the US. Their study is published in a recent issue of Applied Physics Letters.
As the researchers explain, the concept of using magnetic nano-objects to store binary information for magnetic RAM has previously been investigated, but it’s been difficult to find a mechanism to reverse the magnetization inside individual nano-objects. Here, the researchers achieve this reversal by using microwave pulses in combination with a static magnetic field. In this scheme, large and small rotating core frequencies are associated with positive and negative core polarities, respectively. In a positive core polarity, the core is parallel to the applied magnetic field, while in a negative core polarity, the core is antiparallel to the applied magnetic field. An extremely sensitive magnetic resonance force microscope (MRFM) is used to address the resonant frequency of magnetic nanodots’ vortex core rotations, allowing the researchers to control the polarity states of individual nanodots.