A team of researchers at IBM has created the world’s smallest magnet using a single atom which can store one bit of data on it.
Currently, hard disk drives use about 100,000 atoms to store a single bit. The IBM scientists used a scanning tunneling microscope (STM) to build and measure isolated single-atom bits using the holmium atoms.
Then, they used an electrical current to write and read binary data (1s and 0s) on the atom.
Source- The Indian Express