Finding new ways to image spin textures can lead to advancements in data storage and processing with bit sizes at an atomic scale. Current imaging methods involve the use of a type of microscopy in which a magnetic probe hovers above a magnetic surface at a very small distance – a method which can risk damage to the probe head and the surface.

Schlenhoff et al. used spin-polarized scanning tunneling microscopy (SP-STM) to carefully image spin textures at an atomic scale and with high spatial resolution while at a safe distance of up to 8 nm away.

The authors conducted their experiments at low temperatures and in ultra-high vacuum. They found that resonance states evolve in front of magnetic surfaces and that by controlling the tunneling of electrons from the magnetic probe tip into these states allows for imaging the surface at nanometer distances.

“With our new technique, electrons tunnel not directly from the probe tip to the surface, but in so-called resonance states, that are located a few nanometers apart from the surface and exhibit the same magnetic properties as the underlying surface atom,” said author Anika Schlenhoff.

The resonance states discovered boost information and make it accessible at distances further away from the surface.

“The atomic-scale precision of this technique would allow to further shrink the bit size in future data storage devices down to the atomic-scale resulting in an ultrahigh density memory while keeping robust tip-sample distances for the read/write operation,” said Schlenhoff.

The authors are working to adapt their imaging technique to room temperature and realistic ambient conditions.

Source: “Real-space imaging of atomic-scale spin textures at nanometer distances,” by A. Schlenhoff, S. Kovarik, S. Krause, and R. Wiesendanger, Applied Physics Letters (2020). The article can be accessed at https://doi.org/10.1063/1.5145363.