CPM Seminar

Melting and metallization of dense hydrogen

Stanimir Bonev

Dalhousie

Understanding the behavior of compressed hydrogen is one of the long-standing challenges in condensed matter physics. In 1935, Wigner and Huntington predicted that if hydrogen is compressed sufficiently it would become a metal. But so far a metallic form of hydrogen has been attained only at very high temperatures. In this talk, I will discuss ab initio molecular dynamics calculations predicting the melting line and a first order liquid-liquid phase transition from molecular to metallic fluid in compressed hydrogen. The computed melting line has a maximum, which is rather unusual for a close-packed solid structure. I will show that its existence in hydrogen is a result of changes in intermolecular interactions, which occur in the fluid phase at high pressure. The results open up the interesting possibility of finding a near-ground liquid metallic state of dense hydrogen.