Optical purification of materials via electromagnetically induced walking

Natural materials are always mixed with foreign matters which affect their physical or chemical properties. Here, we give an optical method for the precise purification of gaseous state materials. Principle of this method is originated from spin-orbit coupling in electromagnetically induced walking where fingerprints of atoms such as masses and optical transition wavelengths determine walking speed of the atoms. This method could be used for some hardly separable atoms and isotopes depending on the condition of atom coherent time. The present work opens a platform for applications of cold atom technology in the purification of atoms and molecules.PACS numbers: 37.10.Vz, 32.90.+a, 3.75.-b, 42.50.Ct