λ相變

λ（lambda）相變是凝聚态物理学中的一類，將許多有強烈類似特性的系統放在一起，像是超流體、超導體及液晶。這些系統因為在相變的熱力學臨界特性，歸於在同一個普適類。這些系統乍看之下差異很大，但可以用類似的公式描述，而而其相图是相同的。

氦在一般流體和超流體之間，比熱容和不同溫度的變化

若將氦在1标准大气压下降溫，約為2.17 K（λ点）時，會從一般流體氦(I)相變到超流體氦(II)，其比熱容對溫度的圖會類似希臘文的字母λ，因此稱這類的相變為λ相變。

相關條目

• λ點
• 超流体
• 超导现象
• 液晶
• 相變
• 重整化群
• 拓扑缺陷

參考資料

書籍

• Chaikin P. M. and Lubensky T. C. Principles of Condensed Matter Physics (Cambridge University Press, Cambridge) 1995, sect.9.
• Feynman R. P. Progress in Low Temperature Physics Vol.1, edited by C. Gorter (North Holland, Amsterdam) 1955.

期刊論文

• Helfrich, W. Defect model of the smectic A-nematic phase transition. Journal de Physique (EDP Sciences). 1978, 39 (11): 1199–1208. ISSN 0302-0738. doi:10.1051/jphys:0197800390110119900. 
• Nelson, David R.; Toner, John. Bond-orientational order, dislocation loops, and melting of solids and smectic-Aliquid crystals. Physical Review B (American Physical Society (APS)). 1 June 1981, 24 (1): 363–387. Bibcode:1981PhRvB..24..363N. ISSN 0163-1829. doi:10.1103/physrevb.24.363. 
• Dasgupta, C.; Halperin, B. I. Phase Transition in a Lattice Model of Superconductivity. Physical Review Letters (American Physical Society (APS)). 23 November 1981, 47 (21): 1556–1560. Bibcode:1981PhRvL..47.1556D. ISSN 0031-9007. doi:10.1103/physrevlett.47.1556. 
• Williams, Gary A. Vortex-ring model of the superfluidλtransition. Physical Review Letters (American Physical Society (APS)). 26 October 1987, 59 (17): 1926–1929. Bibcode:1987PhRvL..59.1926W. ISSN 0031-9007. PMID 10035370. doi:10.1103/physrevlett.59.1926. 
• Onsager, L. Statistical hydrodynamics. Il Nuovo Cimento (Springer Science and Business Media LLC). 1949, 6 (S2): 279–287. Bibcode:1949NCim....6S.279O. ISSN 0029-6341. S2CID 186224016. doi:10.1007/bf02780991. 
• de Gennes, P.G. An analogy between superconductors and smectics A. Solid State Communications (Elsevier BV). 1972, 10 (9): 753–756. Bibcode:1972SSCom..10..753D. ISSN 0038-1098. doi:10.1016/0038-1098(72)90186-x. 
• Abrikosov, A. A. [unknown title]. Zhurnal Éksperimental'noĭ i Teoreticheskoĭ Fiziki. 1957, 32 (6): 1442 （俄语）.  Translated as: Abrikosov, A. A. On the Magnetic Properties of Superconductors of the Second Group. Soviet Physics JETP. 1957, 5 (6): 1174 [2021-07-22]. （原始内容存档于2020-01-13）. 
• Renn, S. R.; Lubensky, T. C. Abrikosov dislocation lattice in a model of the cholesteric–to–smectic-Atransition. Physical Review A (American Physical Society (APS)). 1 July 1988, 38 (4): 2132–2147. Bibcode:1988PhRvA..38.2132R. ISSN 0556-2791. PMID 9900613. doi:10.1103/physreva.38.2132.