Work

Observation of Δ J = 0 Rotational Excitation in Dense Hydrogens

Year: 2025

Type: article

Abstract: Raman measurements performed on dense H_{2}, D_{2} and H_{2}+D_{2} in a wide pressure-temperature range reveal the presence of the ΔJ=0 rotational excitation. In the gas/fluid state this excitation has zero Raman shift, but in the solid, the crystal field drives it away from the zero value, e.g., ∼75 cm^{-1} at around 50 GPa and 10 K for both isotopes and their mixture. In the case of deuterium, the ΔJ=0 mode splits upon entering phase II suggesting a very complex molecular environment of the broken symmetry phase (BSP). In the fluid state and phases I and II the frequencies (energies) of the ΔJ=0 transition for H_{2} and D_{2} scale neither as rotational (by factor of 2) nor vibrational (by sqrt[2]) modes and appear to be completely isotope independent. This independence on mass marks this transition as unique and a fundamentally different type of excitation from the commonly considered harmonic oscillator and quantum rotor.

Source: Physical Review Letters

DOI: 10.1103/7m51-n6w7

Authors: Jie Feng, Xiao-Di Liu, Haian Xu, Pu Wang, Graeme J. Ackland, Eugene Gregoryanz

Institutions: University of Science and Technology of China, Shanghai Advanced Research in Physical Sciences, University of Edinburgh, Center for High Pressure Science and Technology Advanced Research

Language: English

Topic: High-pressure geophysics and materials

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,750

Funders: National Natural Science Foundation of China, Chinese Academy of Sciences, Youth Innovation Promotion Association of the Chinese Academy of Sciences