Studies of single atom magnets via scanning tunneling microscopy

In the past century, there have been revolutionary inventions and developments in both information and computational devices. The advances of nanotechnology have continued to miniaturize these devices in solid-state platforms. This trend will eventually reach the ultimate limit of single atoms and molecules. Scanning tunneling microscopy and spectroscopy (STM/STS) have been highly useful tools to investigate electronic and magnetic properties of individual atoms, molecules, and nanostructures on surfaces. Manipulating the electron spin degree of freedom at the atomic level may allow us to write, store, and read binary information of the smallest unit – atoms and molecules. At this length scale, quantum mechanics governs the behavior of individual spins and their interactions. Understanding temporal stability, accessibility, and spin lifetime at the atomic scale is essential to exploit the possibilities for using atoms and molecules as a basic unit of memory. This review introduces various STM-based research efforts toward single atom memory realization.