Isotope quantum effects in the metallization transition in liquid hydrogen

Abstract

Quantum effects in condensed matter normally only occur at low temperatures. Here we show a large quantum effect in high-pressure liquid hydrogen at thousands of Kelvins. We show that the metallization transition in hydrogen is subject to a very large isotope effect, occurring hundreds of degrees lower than the equivalent transition in deuterium. We examined this using path integral molecular dynamics simulations which identify a liquid-liquid transition involving atomization, metallization, and changes in viscosity, specific heat and compressibility. The difference between H${}_2$ and D${}_2$ is a quantum mechanical effect which can be associated with the larger zero-point energy in H${}_2$ weakening the covalent bond. Our results mean that experimental results on deuterium must be corrected before they are relevant to understanding hydrogen at planetary conditions.

arXiv comment6 pages, 5 figures. To be published in Physical Review Letters

References in corpus (30)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Van der Waals Density Functional for General Geometries
• Observation of the Wigner-Huntington Transition to Solid Metallic Hydrogen
• Efficient stochastic thermostatting of path integral molecular dynamics
• i-PI 2.0: A Universal Force Engine for Advanced Molecular Simulations
• i-PI: A Python interface for ab initio path integral molecular dynamics simulations
• Thermophysical properties of warm dense hydrogen
• A new equation of state for dense hydrogen-helium mixtures
• Nuclear Quantum Effects and Nonlocal Exchange-Correlation Functionals Applied to Liquid Hydrogen at High Pressure
• Evidence for supercritical behavior of high-pressure liquid hydrogen
• Mass-radius relationships for exoplanets
• A First-order Phase Transition to Metallic Hydrogen
• Kubo-Greenwood Electrical Conductivity Formulation and Implementation for Projector Augmented Wave Datasets
• Benchmark of Exchange-Correlation Functionals for High Pressure Hydrogen using Quantum Monte Carlo
• Equation of state of metallic hydrogen from Coupled Electron-Ion Monte Carlo simulations
• Quantum fluctuations and isotope effects in ab initio descriptions of water
• Fate of density functional theory in high-pressure solid hydrogen
• Conductivity and Dissociation in Metallic Hydrogen: Implications for Planetary Interiors
• Thermodynamic anomalies and three distinct liquid-liquid transitions in warm dense liquid hydrogen
• High-pressure behavior of dense hydrogen up to 3.5 TPa from density functional theory calculations
• Distinct metallization and atomization transitions in dense liquid hydrogen
• Optical properties of high pressure liquid hydrogen across molecular dissociation
• The role of van der Waals and exchange interactions in high-pressure solid hydrogen
• Striking Isotope Effect on the Metallization Phase Lines of Liquid Hydrogen and Deuterium
• Fully Consistent Density Functional Theory Determination of the Insulator-Metal Transition Boundary in Warm Dense Hydrogen
• Lattice stability and high pressure melting mechanism of dense hydrogen up to 1.5 TPa
• A simple thermodynamic model for the hydrogen phase diagram
• Towards the same line of liquid-liquid phase transition of dense hydrogen from various theoretical predictions
• Theory of high pressure hydrogen, made simple
• Appraisal of the realistic accuracy of Molecular dynamics of high pressure hydrogen

Cited by in corpus (4)

• First principles simulations of dense hydrogen
• Deep variational free energy prediction of dense hydrogen solid at 1200K
• Organic compounds in metallic hydrogen
• A Denser Hydrogen Inferred from First-Principles Simulations Challenges Jupiter's Interior Models