Quantum Nucleation

量子核是一种宏观量子现象，它与宏观变量描述的Metastical系统的衰变相结合，这就是稳定相位的核辐射。量子核的概念目前被应用于物理学的各个领域。因此，它对现象的不具有极大的重要意义：超流体超饱和的系统D13-D1 He-D14-D1 He-D14-D1 He-D1 He-D1 He混合是最突出和唯一的系统，用于观察大量量子核，在条件物质中。Firstly， wall effects may be negligible because of the difference of zero-point energy between伊D13伊D1He and伊D14伊D1He atoms。这意味着任何表面都不可能在核化D13和D1 He集中的相位（c阶段）中发挥作用。第二，我们发明的方法来确定D13 D1 He-dilute相位（d-相位）的超饱和状态是一种压力扫描方法，因为我们可以控制扫描速率如此缓慢，几乎是一个问题。 ... More tatic condition is realized.这里，我们报告了从超饱和超流体分离的系统研究的结果，D13-D1 He-D14-D1 He-D14-D1 He-D1 D-D1 D-D1 D-他的混合物。The amount of critical supersaturation、Oracle D23型D2、cr was determined in the wide ranges of the temperature （400-K -500 mK） and the pressure （0 - 8 kg·f/cm型D12型D1）。With the data we constructed the surface of critical supersaturation， ΔX D23 D2，cr （T，P）， which enable us to recognize the overall features of critical supersaturation in superfluid D13 D1He-D14 D1He mixtures。主要的具体功能都是按以下方式观察的。（i） Below about 10 mK，{{X}} D23} D2，cr is almost independent of temperature。（ii）在10 mK以上， Δ X-Y-D-23-D-2，cr增加与温度有关。Nakamura等人半定量分析了理论。它显示了由我们观察到的阶段分离约10 mK是由量子核触发的。第二个事实建议是分裂对核过程的影响。Burmistrov and Satoh theoretically discussed that effect by considering the second sound mode and the diffusion ofイイD13イエD1 He atoms in the d-phase。我们最近的实验性调查对C-和D-相位之间接口的动力学有很强的支持。Less（低）

Quantum nucleation is a kind of macroscopic quantum phenomenon accompanying the decay of metastable system described with a macroscopic variable, that is, the radius of a nucleus of the stable phase. The concept of quantum nucleation is currently applied in various field of physics. So, it is extremely important to obtain the unambiguous evidence of the phenomenon.The system of superfluid supersaturated ィイD13ィエD1He-ィイD14ィエD1He mixture is apparently the most prominent and unique system for observing the bulk quantum nucleation, in a condensed matter. Firstly, wall effects may be negligible because of the difference of zero-point energy between ィイD13ィエD1He and ィイD14ィエD1He atoms. That is, any surface is unlikely to be effective in nucleating the ィイD13ィエD1He-concentrated phase (c-phase). Secondly, our invented method to realize a supersaturated state of the ィイD13ィエD1He-dilute phase (d-phase) is a pressure sweep method, in which we can control the sweep rate so slowly that the almost quasis … More tatic condition is realized.Here, we report the results of the systematic study of the phase separation from supersaturated superfluid ィイD13ィエD1He-ィイD14ィエD1He mixtures of d-phase. The amount of critical supersaturation, ΔXィイD23ィエD2,cr was determined in the wide ranges of the temperature (400μK - 500mK) and the pressure (0 - 8kg・f/cmィイD12ィエD1). With the data we constructed the surface of critical supersaturation, ΔXィイD23ィエD2,cr (T,P), which enable us to recognize the overall features of critical supersaturation in superfluid ィイD13ィエD1He-ィイD14ィエD1He mixtures. The main specific features observed are as follows.(i) Below about 10mK, ΔXィイD23ィエD2,cr is almost independent of temperature.(ii) Above about 10mK, ΔXィイD23ィエD2,cr increases with temperature.The first fact was analyzed with the theory by Nakamura et al. semi-quantitably. It is shown that the phase-separation observed by us below about 10mK is triggered by quantum nucleation. The second fact suggests the effect of dissipation on the nucleation process. Burmistrov and Satoh theoretically discussed that effect by considering the second sound mode and the diffusion of ィイD13ィエD1He atoms in the d-phase. Our recent experimental investigation on the dynamics of the interface between the c-and d-phases strongly supports that consideration. Less