Grüneisen parameter of dense fluid helium at gigapascal pressures and 300 K
Phys. Rev. B 114, 024109 – Published 27 July, 2026
DOI: https://doi.org/10.1103/tzvf-qmx9
Abstract
Utilizing dynamic diamond anvil cell combined with time-resolved temperature-pressure multichannel measurement system, we have measured fluid helium-4′s Grüneisen parameter between 6 and 11 GPa at around 300 K. The measurements yielded the high-pressure volumetric thermal expansion coefficient, with pressure dependence similar to that of dense hydrogen and argon. Unlike the case of low-temperature fluid helium, the unique pressure dependence of the Grüneisen parameter with pressure at room temperature and its jump near the fluid-solid transition may serve as an indicator of localized atomic aggregation of fluid helium under high pressure. This work provides crucial experimental constraints for understanding the thermodynamic behavior and microscopic interactions in dense fluid helium, offering new insights into the high-pressure physics of simple quantum fluids.
