Monday, January 17, 2011

roton

A roton is an elementary excitation, or quasiparticle, in superfluid Helium-4. The dispersion relation of elementary excitations in this superfluid 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.

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talk nineteen to the dozen

  to speak rapidly and without stopping