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 H2 and D2 is a quantum mechanical effect which can be associated with the larger zero-point energy in H2 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.
@article{arxiv.2009.05491,
title = {Isotope quantum effects in the metallization transition in liquid hydrogen},
author = {Sebastiaan van de Bund and Heather Wiebe and Graeme J. Ackland},
journal= {arXiv preprint arXiv:2009.05491},
year = {2021}
}
Comments
6 pages, 5 figures. To be published in Physical Review Letters