Qubits, the quantum analog of a digital bit, are envisioned as the building blocks of the future of computation. The quantum bit is special because of its ability to be in simultaneous values of 0 and 1, while digital bits can only be a 0 or a 1, not both. The calculations of quantum problem become exponentially more difficult as larger qubit computations are required: a 2-qubit calculation is twice as difficult as a 1-qubit calculation, a 3-qubit calculation is twice as difficult as a 2-qubit calculation, and a 51-qubit calculation is 200 trillion times more difficult than that!
Researchers from a Harvard-MIT collaboration use lasers and individual Rubidium atoms to encode a special type of quantum computer known as a quantum simulation. This quantum simulator is the largest of its kind. Each atom represents a single qubit in their computation, and the lasers are used to both address and read out values of each qubit. Dr. Hannes Bernien and Dr. Ahmed Omran, postdoctoral researchers on the 51-qubit simulator, point out that while the atoms are actually all initialized as classical bits, they evolve into a complex quantum mechanical state, resulting in a speedup of their simulation. For a classical system, the same problems would be intractable.
While you shouldn’t expect to see this type of system as a possible upgrade when purchasing your next MacBook, it is a demonstration of the success of using inherently quantum mechanically behaving objects to perform computations that are not feasible by a traditional computer.
Thank you to Dr. Hannes Bernien and Dr. Ahmed Omran at Harvard University, for their explanation of their experiment’s details, procedure, and broader impact.
Probing many-body dynamics on a 51-atom quantum simulator – Nature