论文标题
Bragg-Cherenkov共鸣和超氟氦上的Wigner固体的二极管脱钩
Bragg-Cherenkov resonance and polaron-like decoupling of the Wigner solid on superfluid helium
论文作者
论文摘要
超氟$^{4} \ mathrm {He} $上二维Wigner固体（WS）的非线性极性动力学在理论上在不同的模型和传输方案中以相似性和区别为单位进行了分析。通常根据直流传输模型考虑表面波和与表面凹坑的WS脱钩的Bragg-Cherenkov（BC）共振激发。同时，在AC条件下测量了WS的现场速度特性，并以时间平均数量提出。在这里，使用两种不同的方法研究了基于固定驾驶场或输出电流的两种不同方法，研究了AC条件的WS耦合与表面凹坑的非线性运动方程。证明两种方法都为主要运输特性的第一个谐波提供了相似的结果。在交流理论中，凹式惯性和动量弛豫速率的BC共振具有不对称的形状，这与DC模型的结果形成鲜明对比。即使是相当低的驾驶频率也会影响WS的BC共振和脱钩的幅度。在BC阈值上方，表面凹痕的有效质量与速度振幅的函数强烈振荡，表明多个重耦过程。
Nonlinear polaron-like dynamics of the two-dimensional Wigner solid (WS) on superfluid $^{4}\mathrm{He}$ are theoretically analyzed in different models and transport regimes for their similarities and distinctions. The Bragg-Cherenkov (BC) resonant excitation of surface waves and WS decoupling from surface dimples were usually considered in terms of a dc transport model. At the same time, field-velocity characteristics of the WS are measured under ac conditions and presented for time-averaged quantities. Here the nonlinear equation of motion of the WS coupled to surface dimples is studied for ac conditions using two different approaches based on fixing the driving field or the output current. Both approaches are shown to give similar results for the first harmonics of major transport properties. In the ac theory, the BC-resonances for dimple inertia and the momentum relaxation rate have asymmetrical shapes, which is in contrast with the results of dc models. Even a quite low driving frequency is shown to affect the amplitude of the BC resonance and decoupling of the WS. Above the BC threshold, the effective mass of surface dimples as a function of the velocity amplitude strongly oscillates indicating multiple recoupling processes.
