Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland.
Department of Materials, ETH Zürich, Hönggerbergring 64, CH-8093 Zürich, Switzerland.
Science. 2016 Apr 15;352(6283):318-21. doi: 10.1126/science.aad9898.
A permanent magnet retains a substantial fraction of its saturation magnetization in the absence of an external magnetic field. Realizing magnetic remanence in a single atom allows for storing and processing information in the smallest unit of matter. We show that individual holmium (Ho) atoms adsorbed on ultrathin MgO(100) layers on Ag(100) exhibit magnetic remanence up to a temperature of 30 kelvin and a relaxation time of 1500 seconds at 10 kelvin. This extraordinary stability is achieved by the realization of a symmetry-protected magnetic ground state and by decoupling the Ho spin from the underlying metal by a tunnel barrier.
在没有外磁场的情况下，永磁体保持其饱和磁化强度的很大一部分。在单个原子中实现磁剩磁，可以在物质的最小单位中存储和处理信息。我们表明，吸附在 Ag(100)上的超薄 MgO(100)层上的单个钬 (Ho) 原子在 30 开尔文的温度下表现出磁剩磁，在 10 开尔文时的弛豫时间为 1500 秒。这种非凡的稳定性是通过实现受对称性保护的磁基态以及通过隧道势垒将 Ho 自旋与底层金属解耦来实现的。
