1.
Phys Rev Lett
; 88(19): 195301, 2002 May 13.
Artigo
em Inglês
| MEDLINE
| ID: mdl-12005643
RESUMO
We report neutron-scattering measurements of the phonons in bcc solid 4He. In general, only three acoustic phonon branches should exist in a monatomic cubic crystal. In addition to these phonon branches, we found a new "opticlike" mode along the [110] direction. One possible interpretation of this new mode is in terms of localized excitations unique to a quantum solid.