Electron Arrays in Two Dimensions

他们建议测量液氦表面电子晶格相中声子的线宽，以验证纵向声子线宽的弱耦合理论。该理论预测了线宽与声子频率成反比变化，并预测了线宽的密度和温度依赖关系。据预测，在熔化温度的十分之一左右，线宽将达到最大值。这是由于德拜-沃勒因子使高温下的散射减少所致。在密度低于107/cm的情况下，弱耦合近似有望成立。他们的测量应该检查这一理论的有效性范围。

They propose to measure the linewidth of phonons in the lattice phase of electrons on the surface of liquid helium to check the weak coupling theory of longitudinal phonon linewidths. This theory predicts the linewidths to vary inversely with the phonon frequency, and predicts the density and temperature dependence of the linewidth. A maximum in the linewidth is predicted at about one-tenth the melting temperature. This results from a reduction in scattering at high temperatures due to the Debye-Waller factor. The weak coupling approximation is expected to hold for densities below 107/cm. Their measurements should check the range of validity of this theory.