A possible extension (λ^’) of the λ curve of liquid helium beyond the T, p boiling line, i.e., into the region of a metastable liquid state, is examined. The relation between the slope of the λ curve dp/dT_λ and the sign of the thermal expansion coefficient of liquid helium a_p is discussed. Experimental data for a_p are analyzed using thermodynamic equations to reveal that the derivative dp/dT_λ changes sign in the metastable region. As a result, the shape of the λ^’ extension becomes similar to that of the pressure-shifted Bose-condensation line of an ideal ⁴He gas. The position of the λ^’ curve is not entirely arbitrary due to the spinodal nature of stretched liquid helium.

PACS: 67.40.−w, 67.40.Kh, 67.90.+z (all) DOI: 10.1070/PU2000v043n05ABEH000690 URL: https://ufn.ru/en/articles/2000/5/e/ 000165080500005 Citation: Skripov V P "Extension of the λ curve of 4He into the region of the metastable state of liquid helium" Phys. Usp. 43 515–519 (2000) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Оригинал: Скрипов В П «Продолжение λ-кривой 4Не в область метастабильного состояния жидкого гелия» УФН 170 559–563 (2000); DOI: 10.3367/UFNr.0170.200005f.0559