Phase Separation in Cold Para- H2 D2 Clusters

Low temperature phase separation in mixtures of H3e and H4e isotopes is a unique property of quantum fluids. Hydrogen has long been considered as another potential quantum liquid and has been predicted to be superfluid at T≤1 K, well below freezing temperature of ≈14 K. Phase separation has also been predicted in mixtures of para-H2 and D2 at temperatures ≤3 K. To defer the freezing, we produced clusters containing para-H2 and D2 at an estimated temperature of ≈2 K whose state was studied by vibrational Raman spectroscopy. The results indicate that the clusters are liquid and show the phase separation of the isotopes. The phase separation is further corroborated by the quantum molecular dynamics simulation.Received 26 January 2024Accepted 11 April 2024DOI:https://doi.org/10.1103/PhysRevLett.132.206001© 2024 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAtomic & molecular clustersPhase separationTechniquesAb initio molecular dynamicsCoherent Raman in a low pressure gasCondensed Matter, Materials & Applied PhysicsAtomic, Molecular & Optical