Magnetic exchange force microscopy with atomic resolution

摘要: The ordering of neighbouring atomic magnetic moments (spins) leads to important collective phenomena such as ferromagnetism and antiferromagnetism. A full understanding magnetism on the nanometre scale therefore calls for information arrangement spins in real space with resolution. Spin-polarized scanning tunnelling microscopy accomplishes this but can probe only conducting materials. Force be used any sample independent its conductivity. In particular, force is well suited exploring ferromagnetic domain structures. However, resolution cannot achieved because data acquisition involves sensing long-range magnetostatic forces between tip sample. Magnetic exchange has been proposed overcoming limitation: by using an microscope a tip, it should possible detect short-range spins. Here we show prototypical antiferromagnetic insulator, (001) surface nickel oxide, that indeed reveal both atoms their simultaneously. contrast previous attempts implement method, use external field align polarization at apex so optimize interaction This allows us observe direct coupling atom are closest each other, thereby demonstrate potential investigations inter-spin interactions level.