Largest object/particle that possesses wave properties...

[dcl]

The largest object that I know of that posesses wave properties are electrons. Has anyone got an entire atom to possess wave properties?]

Also, does the whole structure/model of an atom break down when you consider the smaller particles to be waves and not particles?

[GRQC]

There has been suggestion/evidence that complex (protein) molecules can be described as quantum objects. I'm not currently aware of the literature references, but if you search for protein folding, you'll find discussion that it requires wavefunction collapse to occur efficiently.

[NateTG]

What do you mean by large? Radio photons have wavelengths in the meters.

[ZapperZ]

Originally posted by dcl
The largest object that I know of that posesses wave properties are electrons. Has anyone got an entire atom to possess wave properties?]

Also, does the whole structure/model of an atom break down when you consider the smaller particles to be waves and not particles?

I am not exactly sure what you mean by an "object". We definitely know that a neutron has wave properties or else all those neutron scattering experiments in condensed matter would be rather useless. So that already shows a wavelike properties for an "object" larger than electrons.

Secondly, if you can consider an "object" as an atom or molecule, then we have seen wavelike properties in objects as big as a C60 and C70 buckyballs,[1] and even as large as a biomolecule of tetraphenylporphyrin[2] that has a diameter of about 2 nm (more than twice as big as a C60 molecule).

Zz

[1] M. Arndt et al., Nature v.401, p.680 (1999).
[2]L. Hackermüller et al., Phys. Rev. Lett. v.91, p.090408 (2003).

[Chi Meson]

Technically, anything with momentum can be described as a wave; that is, the deBroglie wavelength is a function of momentum and can be calculated for even a planet.

But as for particles that exhibit classic wave phenomena such as diffraction, I know it has been observed for protons neutrons and alpha particles.

I'm glad to hear about the buckyballs too.

[russ_watters]

According to the theory, all matter should display wave properties. The largest that I know of that we have observed in experiments are whole atoms being sent through the double-slit experiment.

[Njorl]

I would say that any object that you can clearly define as a single object can be described as a particle or wave. A human is difficult to describe. Where does the human stop? Do we count dead skin cells, dandruff, the bacteria living on our skin? It isn't that these things are not governable by wave-particle duality, it is just an uninteresting way to look at them. A black hole though, is easy to define. Everything inside the event horizon is part of the object, everything outside is not.

Njorl