Nunomura S, Samsonov D, Goree J
Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA.
Phys Rev Lett. 2000 May 29;84(22):5141-4. doi: 10.1103/PhysRevLett.84.5141.
Transverse shear waves were observed experimentally in a two-dimensional screened Coulomb crystal. They were excited by applying a chopped laser beam to a 2D dusty plasma, i.e., a monolayer of charged microspheres levitated in a plasma. Measurements of the dispersion relation reveal an acoustic, i.e., nondispersive, character over the entire range of wave numbers measured, 0.2<k(r)a/pi<0.7, where a is the interparticle spacing. Comparison to theory provides a measurement of the particles' charge.
在二维屏蔽库仑晶体中通过实验观测到了横向剪切波。通过向二维尘埃等离子体（即悬浮在等离子体中的单层带电微球）施加斩波激光束来激发这些波。色散关系的测量结果表明，在所测量的整个波数范围内，即0.2＜k(r)a/π＜0.7（其中a是粒子间间距），呈现出声学特性，即非色散特性。与理论的比较给出了粒子电荷的测量值。
