Conductivity and Dissociation in Metallic Hydrogen: Implications for Planetary Interiors

TL;DR

This study measures the optical conductivity of liquid metallic hydrogen under high pressure, revealing its largely atomic state and implications for planetary interiors, especially gas giants like Jupiter.

Contribution

It provides the first detailed optical conductivity measurements of LMH at high pressures using the Drude model, highlighting its atomic dissociation and planetary relevance.

Findings

Electrical conductivity of 11,000-15,000 S/cm

LMH is largely atomic and degenerate

Implications for planetary structure models

Abstract

Liquid metallic hydrogen (LMH) was recently produced under static compression and high temperatures in bench-top experiments. Here, we report a study of the optical reflectance of LMH in the pressure region of 1.4-1.7 Mbar and use the Drude free-electron model to determine its optical conductivity. We find static electrical conductivity of metallic hydrogen to be 11,000-15,000 S/cm. A substantial dissociation fraction is required to best fit the energy dependence of the observed reflectance. LMH at our experimental conditions is largely atomic and degenerate, not primarily molecular. We determine a plasma frequency and the optical conductivity. Properties are used to analyze planetary structure of hydrogen rich planets such as Jupiter.