Spin sensing and magnetic design, one atom at a time

Insight into the quantum world requires access to individual spins and the ability to manipulate their interactions with their environment. With the development of scanning probe microscopy, it has become possible to access the spin of an individual atom with unprecedented resolution. I will review exciting developments based on scanning tunneling microscopy and atomic force microscopy (STM/AFM) which enables magnetic imaging at the single atom level. Using iron atoms as an example, I will discuss how we can characterize the magnetic properties of an individual atom, such as its magnetization and magnetic anisotropy. With this understanding, I will discuss how we measure the exchange interactions between atoms with a variety of methods, including inelastic tunneling, spin-polarized STM, and magnetic exchange force microscopy. To this end, I will exemplify how these techniques can be combined with atomic manipulation to realize atomic-scale magnetic memory, as well as nanomagnets aimed at understanding how the environment effects its stochastic behavior. Finally, I will discuss our recent efforts at spin-polarized imaging at mK temperatures in our recently constructed SPIN labs.