Department of Physics, Brown University, Providence, Rhode Island 02912, USA.
J Chem Phys. 2012 Jun 28;136(24):244510. doi: 10.1063/1.4730747.
We introduce a compact finite-temperature density functional model to study electron self-trapping in both liquid and vapor (3)He and (4)He. This model can quantitatively reproduce the most essential thermodynamic properties of (3)He and (4)He along their liquid-vapor coexistence lines. The structures and energetics of self-trapped electron bubbles on the 1S ground state and 1P excited state are particularly investigated. Our results show that 1S and 1P bubbles exist in liquid at any temperature, whereas 1S bubbles exist in vapor only above 1.6 K in (3)He and above 2.8 K in (4)He, 1P bubbles exist in vapor only above 2.5 K in (3)He and 4.0 K in (4)He. An initially spherical 1P bubble is unstable against deformation towards a peanut shape. In liquid, a peanut-shaped 1P bubble is held from fission by surface tension until reaching the liquid-vapor critical point, whereas in vapor it always splits into two smaller bubbles. The existence of 1P bubbles in finite-temperature liquid helium and their fission instability in helium vapor reveal interesting physics in this system.
我们介绍了一个紧凑的有限温度密度泛函模型，用于研究液体和蒸汽（3）He 和（4）He 中的电子自陷。该模型可以定量再现（3）He 和（4）He 在其液-气相共存线上的最基本热力学性质。特别研究了 1S 基态和 1P 激发态自陷电子泡的结构和能态。我们的结果表明，1S 和 1P 泡在任何温度下都存在于液体中，而 1S 泡仅在（3）He 中高于 1.6 K 和（4）He 中高于 2.8 K 时存在于蒸汽中，1P 泡仅在（3）He 中高于 2.5 K 和（4）He 中高于 4.0 K 时存在于蒸汽中。初始为球形的 1P 泡会因变形而变得不稳定，呈花生形状。在液体中，花生形 1P 泡由于表面张力而保持不裂变，直到达到液-气相临界点，而在蒸汽中，它总是分裂成两个较小的泡。有限温度液氦中 1P 泡的存在及其在氦蒸汽中的裂变不稳定性揭示了该系统中的有趣物理现象。
