Engineering atomic-scale magnetic fields by dysprosium single atom magnets

Atomic scale engineering of magnetic fields is a key ingredient for miniaturizing quantum devices and precision control of quantum systems. This requires a unique combination of magnetic stability and spin-manipulation capabilities. Surface-supported single atom magnets offer such possibilities, where long temporal and thermal stability of the magnetic states can be achieved by maximizing the magnet/ic anisotropy energy (MAE) and by minimizing quantum tunnelling of the magnetization. Here, we show that dysprosium (Dy) atoms on magnesium oxide (MgO) have a giant MAE of 250 meV, currently the highest among all surface spins. Using a variety of scanning tunnelling microscopy (STM) techniques including single atom electron spin resonance (ESR), we confirm no spontaneous spin-switching in Dy over days at approximate to 1 K under low and even vanishing magnetic field. We utilize these robust Dy single atom magnets to engineer magnetic nanostructures, demonstrating unique control of magnetic fields with atomic scale tunability. Single atom magnets on surfaces offer potentially long lived and stable spin states, particular lanthanides, which can be adsorbed onto Magnesium Oxide. Here, the authors report on Dysprosium adsorbed onto Magnesium Oxide, which exhibits large magnetic anisotropy energy, and a spin life time of several days at low temperatures

Automated summary

Atomic scale engineering of magnetic fields is crucial for miniaturizing quantum devices and precise control of quantum systems. Surface-supported single atom magnets with a giant magnetic anisotropy energy exhibit long-term stability of spin states at low temperatures. Dy adsorbed onto MgO shows a high MAE and a life time of several days at low temperatures, making it a promising candidate for magnetic nanostructures.