A Spectroscopic Study of the Insulator–Metal Transition in Liquid Hydrogen and Deuterium
Abstract
The insulator‐to‐metal transition in dense fluid hydrogen is an essential phenomenon in the study of gas giant planetary interiors and the physical and chemical behavior of highly compressed condensed matter. Using direct fast laser spectroscopy techniques to probe hydrogen and deuterium precompressed in a diamond anvil cell and laser heated on microsecond timescales, an onset of metal‐like reflectance is observed in the visible spectral range at P >150 GPa and T ≥ 3000 K. The reflectance increases rapidly with decreasing photon energy indicating free‐electron metallic behavior with a plasma edge in the visible spectral range at high temperatures. The reflectance spectra also suggest much longer electronic collision time (≥1 fs) than previously inferred, implying that metallic hydrogen at the conditions studied is not in the regime of saturated conductivity (Mott–Ioffe–Regel limit). The results confirm the existence of a semiconducting intermediate fluid hydrogen state en route to metallization.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 27, 2019
- Source ID
- 10.1002/advs.201901668
Entities
People
- Alexander Goncharov
- Mohammad F. Mahmood
- Nicholas Holtgrewe
- R. Stewart Mcwilliams
- Sergey Lobanov
- Shuqing Jiang
- Zachary M. Geballe
Organizations
- Army Research Office
- Carnegie Institution for Science
- Chinese Academy of Sciences
- Engineering and Physical Sciences Research Council
- GFZ Helmholtz Centre for Geosciences
- Howard University
- National Natural Science Foundation of China
- National Science Foundation
- University of Edinburgh