Nucleation of theABtransition in superfluidHe3: Surface effects and baked Alaska
Nucleation of theABtransition in superfluidHe3: Surface effects and baked Alaska
复制标题
超流体He3中AB转变的成核：表面效应和烘烤的阿拉斯加
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
D. Osheroff
中科院分区：
文献类型：
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作者：
P. Schiffer;D. Osheroff
超流体的{italA}和{italB}相之间的一级相变他在近20年的时间里一直是氦物理学中的一个杰出的谜团。这两个相之间的体积自由能差异很小，再加上与{italAB}界面相关的相对较大的表面能，导致了一个异常大的形核临界半径，其量级为1{u}m，这表明过冷的{italA}相相对于均匀形核的寿命远远超过了宇宙的年龄。然而，高温相的各向异性使表面的去配对效应最小化，从而使传统的异质成核变得不太可能。据报道，最近的实验支持一种曾被提出的更为奇异的形核机制：莱格特的‘’烘焙阿拉斯加‘’模型，在该模型中，宇宙射线穿透过冷的{首都A}相，使{首都B}相成核。讨论了这些实验的结果，并对未来的工作进行了展望。
The first-order phase transition between the {ital A} and {ital B} phases of superfluid {sup 3}He has remained an outstanding mystery in helium physics for nearly 20 years. The small difference in bulk free energies between the two phases, combined with the relatively large surface energy associated with the {ital AB} interface, leads to an anomalously large critical radius for nucleation, of order 1 {mu}m, suggesting a lifetime for the supercooled {ital A} phase against homogeneous nucleation far beyond the age of the universe. Yet anisotropy of the high-temperature phase minimizes the depairing effects of surfaces, thus making conventional heterogeneous nucleation unlikely. Recent experiments have been reported that lend support to one of the more exotic nucleation mechanisms ever proposed: Leggett`s ``baked Alaska`` model, in which the {ital B} phase is nucleated by cosmic rays penetrating the supercooled {ital A} phase. The results of these experiments are discussed, along with the prospects for future work.