论文标题
微观动力学和液氦中的Bose-Einstein凝结
Microscopic dynamics and Bose-Einstein condensation in liquid helium
论文作者
论文摘要
我们回顾液体理论中涉及的基本问题，包括经典液体和量子液体。了解经典液体涉及探索其微观动态及其后果的细节。在这里，我们将相同的一般思想应用于量子液体。我们讨论液态氦气中的动量凝结，这与液体中的微观动力学和液态原子的高迁移率一致。我们建议移动过境原子在有限的能源状态下积聚，在该状态下，该速度接近声音的速度。在这种状态下，运输能量接近零点能。在动量空间中，积累在一个球体上以原子间间距设定的半径进行操作，并且对应于零净动量。我们表明，这张照片得到了实验的支持，包括在预测能量下超出氟化原子下方的氦原子的动能和散射强度的尖锐峰。我们讨论了这张照片的含义，包括宏观波函数和超流量。评估超流体过渡温度在实验值的15％以内。
We review fundamental problems involved in liquid theory including both classical and quantum liquids. Understanding classical liquids involves exploring details of their microscopic dynamics and its consequences. Here, we apply the same general idea to quantum liquids. We discuss momentum condensation in liquid helium which is consistent with microscopic dynamics in liquids and high mobility of liquid atoms. We propose that mobile transit atoms accumulate in the finite-energy state where the transit speed is close to the speed of sound. In this state, the transit energy is close to the zero-point energy. In momentum space, the accumulation operates on a sphere with the radius set by interatomic spacing and corresponds to zero net momentum. We show that this picture is supported by experiments, including the kinetic energy of helium atoms below the superfluid transition and sharp peaks of scattered intensity at predicted energy. We discuss the implications of this picture including the macroscopic wave function and superfluidity. The superfluid transition temperature is evaluated to be within 15% of the experimental value.
