Markovich T, Polturak E, Bossy J, Farhi E
Physics Department, Technion-IIT, Haifa, Israel 3200.
Phys Rev Lett. 2002 May 13;88(19):195301. doi: 10.1103/PhysRevLett.88.195301. Epub 2002 Apr 30.
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.
我们报告了体心立方固态⁴He中声子的中子散射测量结果。一般来说,单原子立方晶体中应该只存在三个声学声子分支。除了这些声子分支外,我们在[110]方向上发现了一种新的“类光学”模式。对这种新模式的一种可能解释是基于量子固体特有的局域激发。