Regensburg 2019 – wissenschaftliches Programm
MA 45.1: Hauptvortrag
Donnerstag, 4. April 2019, 10:30–11:00, H15
Enhancing quantum coherence of magnetic atoms on a surface — •Yujeong Bae1,2,3, Kai Yang2, Philip Willke1,3, Taeyoung Choi1,3, Andreas J. Heinrich1,3, and Christopher P. Lutz2 — 1Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, Republic of Korea — 2650 Harry Rd — 3Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
Coherent control of spin states is of central importance in spin-based information processing and spintronic devices. However, the spin coherence of individual atoms on a surface is easily disrupted by interaction with environment such as electric or magnetic field noise as well as unwanted coupling with neighboring spins. Here we demonstrate that a singlet-triplet transition in a pair of antiferromagnetically coupled spin-1/2 atoms yields enhanced spin coherence compared to individual atoms. We used scanning tunneling microscope to assemble two hydrogenated titanuim atoms on MgO(001). At a precisely selected spacing that gives a large interaction energy between two atoms, we obtain spin states having a high degree of protection from disrupting fields, and also provides thermal initialization into the singlet state. We show that a two level system composed of these singlet and triplet states is insensitive to global and local magnetic field variation, resulting in longer spin coherence times compared to individual atoms.