A matter-wave interferometer for large molecules has been devised
and demonstrated for the first time.
For many years scientists have studied the proposition that things
we normally think of as particles, such as electrons, should also have
Indeed studies of beams of electrons, neutrons, even whole atoms, have
confirmed that particles can be viewed as a series of traveling waves
which diffracted when they pass through a grating or through slits.
These waves could even interfere with each other, resulting in characteristic
patterns captured by particle detectors.
In this way, in 1999 Anton Zeilinger and his colleagues at the University
of Vienna demonstrated the wave nature of carbon-60 molecules by diffracting
them (in their wave manifestation) from a grating (Update 453).
Now the same group, using a full interferometer consisting of three
gratings with wider grating spacings and a more efficient detector setup,
observe a sharp interference pattern.
Moreover, because the beam of particles used, carbon-70 molecules at
a temperature of 900 K, are themselves in an excited state (undergoing
3 rotational and 204 vibrational modes of internal motion), it should
be possible to study the way in which an atom wave, or in this case
a macromolecular wave, becomes decoherent (that is, loses its wavelike
character) because of thermal motions and other interactions with its
environment. Thus this type of interferometer experiment will be useful
in studying the borderland between the quantum and classical worlds.
The researchers (contact Bjorn Brezger, firstname.lastname@example.org, University
of Vienna) are aiming to study the wave properties of even larger composite
objects, mid-sized proteins. (Brezger
et al., Physical Review Letters, 11 March 2002; see
also Professor Zeilinger's website.)