Whereas normal computers use a string of zeroes and ones (bytes) to represent data, experimental quantum computers use qubits, which can be a zero, one, or simultaneously both. On 20 December 2001, IBM’s Almaden Research Center, San Jose, California, USA, announced that they had used a 7-qubit quantum computer to calculate the factors of the number 15. They used a billion billion molecules that have seven nuclear spins for the calculation.
Consisting of the nucleii of five atoms of fluorine and two of carbon, these molecules are able to to interact with each other as qubits.