In the vocabulary of von Klitzing’s Ph.D. thesis, his discovery of 1980 could
be called ‘galvanomagnetic properties of a two-dimensional electron gas in
strong magnetic fields’. This special electron gas, as von Klitzing used it, exists
in a carefully prepared metal–oxide–silicon field-effect transistor or MOSFET.
This type of transistor is the workhorse of modern electronics, because
very many can be placed on a small flat silicon crystal, a ‘chip’, which needs
to be structured on one side only. In one kind of MOSFET the crystal itself,
the substrate, is acceptor-doped, i.e., p-type.