The qubits with which Vandersypen and his colleagues are working consist of individual electrons that are kept in silicon enclosed by electrodes. Using magnetic and electrical fields, the researchers can control the spin of the particles. As with transistors on chips in current computers, it should be possible to couple qubits together on a chip.


The major advantage is that, unlike the normal bit that only has two separate states, zero or one, the quantum bit (or qubit) can be zero and one simultaneously. This is called superposition – a privilege of quantum mechanics – the electron spin can be left and right at the same time. So three qubits can thus consist of two to the third (2x2x2) eight quantum states at the same time. And 10 qubits can handle two to the tenth, or 1,024 simultaneous states. A quantum computer should be able to carry out simultaneous calculations in all different combinations.


The hope is that quantum computers will thus be able to solve complicated calculations that are too complicated even for the best super computers, such as calculating the properties of molecules and materials. (TvD)