论文标题
在低温下解决液态氦气中声音传播的难题
Resolving the puzzle of sound propagation in liquid helium at low temperatures
论文作者
论文摘要
实验数据表明，在低于1 K的温度下，液态氦气中的压力对密度有立方体依赖性。因此，声音尺度是压力的立方根。在临界压力点附近，此速度接近零，从而使临界压力为负，因此表明空化不稳定性状态。我们证明，要解释这一依赖性，必须将液氦视为三种量子bose液体的混合物：稀释（Gross-pitaevskii-type）Bose-Einstein冷凝物，Ginzburg-sobyanin-type type fluid和Aboogarithmic superpluid。因此，这种混合物的动力学是通过量子波方程来描述的，量子波方程不仅包含有关凝聚力波函数的多项式（Gross-Pitaevskii和Ginzburg-sobyanin）非线性的，而且还包含非多物质对数非固定性。我们在模型中得出了状态和声音速度的方程，并显示了他们与实验的一致性。
Experimental data suggests that, at temperatures below 1 K, the pressure in liquid helium has a cubic dependence on density. Thus the speed of sound scales as a cubic root of pressure. Near a critical pressure point, this speed approaches zero whereby the critical pressure is negative, thus indicating a cavitation instability regime. We demonstrate that to explain this dependence, one has to view liquid helium as a mixture of three quantum Bose liquids: dilute (Gross-Pitaevskii-type) Bose-Einstein condensate, Ginzburg-Sobyanin-type fluid, and logarithmic superfluid. Therefore, the dynamics of such a mixture is described by a quantum wave equation, which contains not only the polynomial (Gross-Pitaevskii and Ginzburg-Sobyanin) nonlinearities with respect to a condensate wavefunction, but also a non-polynomial logarithmic nonlinearity. We derive an equation of state and speed of sound in our model, and show their agreement with experiment.
