Prof. Isaac F. Silvera [Lyman Laboratory of Physics, Harvard University]

Title: A First-order Phase Transition to Metallic Hydrogen

Time: 10:00 - 11:00am, April 28, Tuesday
Place: Auditorium room 410, Building 6, HPSTAR (Shanghai)
Host: Ho-Kwang Mao

Abstract:

The insulator-metal transition in hydrogen is one of the most outstanding problems in condensed matter physics. The high-pressure metallic phase is currently predicted to be liquid atomic from T=0 K to very high temperatures. We have conducted measurements of optical properties of hot dense hydrogen in the region of 1.1-1.7 Mbar and up to 2200 K. Pressurized samples are pulse laser heated and observed using time resolved spectroscopy. We observe a first-order phase transition accompanied by changes in transmittance and reflectance characteristic of a metal. The phase line of this transition has a negative slope in agreement with theories of the long predicted plasma phase transition.ing etc.

Biography of the Speaker:

Prof. Isaac Silvera is a Thomas D. Cabot Professor of the Natural Sciences in Harvard University. He obtained his Ph.D. from University of California, Berkeley in 1965. Prof. Silvera's research is in both condensed matter and physics of cold particles. His interests are in ultra high pressure and low-temperature physics of quantum fluids.

I. F. Silvera, "The solid molecular hydrogens in the condensed phase: fundamentals and static properties". Rev. Mod. Phys. 52: 393 (1980).

I. F. Silvera, "Metallic hydrogen," in The Metal-Insulator Transitions Revisited, ed. P. Edwards and C.N. Rao, (Taylor and Francis, London, 1995).

N. H. Chen, E. Sterer, and I. F. Silvera, "Extended infrared studies of high pressure hydrogen". Phys. Rev. Lett. 76: 1663 (1996).

L. Cui, N. H. Chen, and I. F. Silvera, "Excitations, order parameters, and phase diagram of solid deuterium at megabar pressures". Phys. Rev. B 51: 14987 (1995).

J. Tempere, I. F. Silvera, and J. T. Devreese, "The effect of pressure on  statics, dynamics and stability of multielectron bubbles," Phys. Rev. Lett., vol. 87, pp. 275301-277304, 2001.

I. F. Silvera, J. Tempere, J. Huang, and J. DeVreese, "Multi-electron bubbles under pressure," presented at Frontiers of High Pressure Research II: Application of High Pressure to Low Dimensional Novel Electronic Materials, 2001.