论文标题
超量子液体的相图
The phase diagram of ultra quantum liquids
论文作者
论文摘要
我们讨论氦质量小于4原子质量单位的假设同位素的相图的依赖性。我们认为，随着核质量的降低，超氟相变的温度（实际HE-4中约2.2 K）增加，而液态气临界点的温度（实际HE-4中约5.2 k）降低。我们讨论当两个温度相互接近时可能发生的各种情况以及超氟和液态加气相变的顺序参数相互作用。最简单的情况，在核质量，温度和压力的特定值下，这两个顺序参数都可以通过对Landau理论的分析来排除。我们认为，在最有可能的情况下，随着核质量的减少，首先，分隔超流体和正常流体相的线出现了三个智能点，然后在超级流体相变的一阶部分下，临界点消失了，最终三个智力点消失了。当两体散射长度越过零时，相图的最后一个变化发生，这对应于约1.55 U的核质量。我们开发了一种定量理论，该理论允许人们确定这一点附近的相图。最后，我们讨论了几种物理实现此类液体的方法。
We discuss the dependence of the phase diagram of a hypothetical isotope of helium with nuclear mass less than 4 atomic mass units. We argue that with decreasing nucleus mass, the temperature of the superfluid phase transition (about 2.2 K in real He-4) increases, while that of the liquid-gas critical point (about 5.2 K in real He-4) decreases. We discuss various scenarios that may occur when the two temperatures approach each other and the order parameters of the superfluid and the liquid-gas phase transitions interact with each other. The simplest scenario, in which both order parameters become critical at particular values of the nuclear mass, temperature, and pressure, can be ruled out through on an analysis of the Landau theory. We argue that in the most likely scenario, as the nuclear mass decreases, first, a tricritical point appears on the line separating the superfluid and the normal fluid phase, then the critical point disappears under the first-order part of superfluid phase transition line, and in the end the tricritical point disappears. The last change in the phase diagram occurs when the two-body scattering length crosses zero, which corresponds to the nuclear mass of about 1.55 u. We develop a quantitative theory that allows one to determine the phase diagram in the vicinity of this point. Finally, we discuss several ways to physically realize such liquids.
