IBM has made a breakthrough in quantum computing by demonstrating a way to control the quantum behavior of individual atoms. This discovery presents a new cornerstone for quantum computing. The team demonstrated the use of individual atoms as quantum bits for processing of quantum information. Quantum bits are the basic elements of quantum computer’s ability to process information. IBM’s breakthrough marks the first time a single-atom qubit has been implemented using a scanning tunnel microscope (STM). STM can image and locate each atom qubit to precisely control the arrangement of nearby qubit atoms.
The principle of STM is to scan the ultra-sharp tip near the surface to sense the arrangement of individual atoms, and the tip of the needle can pull or carry the atom into the desired arrangement. The basic unit of information in a computer is a bit with a value of 0 or 1. A quantum bit can be a “0” or “1” that is also called an overlay state. State is a basic feature of quantum mechanics. IBM uses the quantum properties of titanium atoms called spins to represent a qubit. The spin properties make each titanium atom magnetic, so it acts like a small compass.
Each titanium atom has a north-south magnetic pole, and the two magnetic orientations define the “0” or “1” of the quantum bit. IBM places titanium atoms on the surface of the selected ultra-thin magnesium oxide to protect its magnetism and demonstrate its quantum personality. The scientists then applied high-frequency radio waves, microwaves, to atoms. Microwaves come from the top of the microscope, allowing the team to control the direction of the atoms. When tuned to the correct frequency, the titanium atom performs a “quantum dance” in which the pole rotates and ends in the desired direction. This dance, or rabbi oscillation, is very fast and takes 20 nanoseconds to make the quantum bit sway back and forth. Atoms end in binary “0” or “1”, depending on the time of action of the radio waves.