ON POSSIBILITY OF SPIN-POLARIZED ATOMIC-FORCE MICROSCOPY

A possible way of realizing an atomic force microscope with spin-resol ving properties is analysed. A model is furnished where the tip of the microscope is made up of a semiconductor in which the electron spins are oriented by interband absorption of circularly polarized light. It is shown by using a time-dependent perturbation theory that a spin-de pendent force will appear between the tip and the surface of a ferroma gnetic sample. This force is caused by tunneling splitting of the elec tronic levels of the tip and the sample. Its magnitude is estimated to be of the order of 1-10 pN. A principle of practical operation and so me applications of spin-sensitive atomic force microscopes are discuss ed.