2006-08-18 01:26:25 · 6 answers · asked by amirpouryousef 1 in Science & Mathematics ➔ Physics
One of the HYPOTHETICAL energy quanta, along with phonons, associated with the behaviour of liquid helium 2. It can be compared with second sound, which is a transfer of heat much faster than conduction or convection, and which is only observed in helium 2. Waves of temperature resembling sound waves travel at speeds of about 20 mtrs per second.
2006-08-23 04:46:55 · answer #1 · answered by ? 2 · 0⤊ 0⤋
It is an excitation of superfluid helium 4. Check out the links the others gave. One interesting thing is that the phonon/roton excitation dispersion almost looks like what you'd expect in a band-structure solid, just not quite. The initial linear dispersion relation, and the fact that the roton doesn't quite get back to zero energy, are in some sense the signatures of superfluidity.
2006-08-18 11:43:40 · answer #2 · answered by Benjamin N 4 · 0⤊ 0⤋
A roton is an excitation in superfluid Helium-4. Its dispersion relation shows a linear increase from the origin, but exhibits first a maximum and then a minimum in energy as the momentum increases. Excitations with momenta in the linear region are called phonons; those with momenta close to the minimum are called rotons. Excitations with momenta near the maximum are sometimes called maxons.
2006-08-18 08:33:32 · answer #3 · answered by Anonymous · 0⤊ 0⤋
A roton is an excitation in superfluid Helium-4. A graph of the energy vs. the momentum of such an excitation increases linearly from the origin, but exhibits first a maximum and then a minimum in energy as the momentum increases. Excitations with momenta in the linear region are called phonons; those with momenta close to the minimum are called rotons. Excitations with momenta near the maximum are sometimes called maxons.----Roton also refers to the Roton SSTO spacecraft design.
2006-08-18 08:32:37 · answer #4 · answered by Brody 3 · 0⤊ 0⤋
A roton is an excitation in superfluid Helium-4. Its dispersion relation shows a linear increase from the origin, but exhibits first a maximum and then a minimum in energy as the momentum increases. Excitations with momenta in the linear region are called phonons; those with momenta close to the minimum are called rotons. Excitations with momenta near the maximum are sometimes called maxons.
2006-08-18 08:31:46 · answer #5 · answered by megalomaniac 3 · 0⤊ 0⤋
do you mean rotation? look that up in your book/google and see what you come up with
2006-08-18 08:34:23 · answer #6 · answered by cornelius jebediah dinglebottom 2 · 0⤊ 0⤋