Phys.org September 1, 2020
An international team of researchers (the Netherlands, Chile, Spain) has shown that it is possible to gain independent access to both the spin and orbital degrees of freedom of a single atom, inciting and probing excitations of each moment. By coordinating a single Fe atom atop the nitrogen site of the Cu2N lattice, they created a single-atom system with a large zero-field splitting and an unquenched uniaxial orbital moment that closely approaches the free-atom value. They demonstrated a full reversal of the orbital moment through a single-electron tunneling event between the tip and Fe atom, a process that is mediated by a charged virtual state and leaves the spin unchanged. The discovery could make it possible to store two bits of information in one atom. The ability to store bits in individual atoms would increase the current maximum storage capacity by many thousands of times. However, the researchers warn that atomic data storage is still a long way off…read more. Open Access TECHNICAL ARTICLE
Fe atoms atop the nitrogen site of the Cu2N surface. Credit: npj Quantum Materials volume 5, Article number: 60 (2020)