Revisiting metallization boundary of warm dense helium in a wide ρ-T regime from ab initio study.
The knowledge of the metallization of warm dense helium has important implications for understanding the thermal histories, stellar structure and magnetic field environment of giant planets. However, it is also a pendent scientific topic. For a revisiting into the properties of warm dense helium, we performed extensive quantum Langevin molecular dynamic simulations and electronic structure calculations to study helium over a very wide range of density (ρ = 1~24 g/cm3) and temperature (T = 10~160 kK). The dependencies of helium band gap on ρ and T were presented and a metallization boundary of helium was thus determined by gap closure. Such a boundary is further identified by the calculated electrical conductivity and optical reflectivity based on Kubo-Greenwood formula: along the boundary, the electrical conductivities are found to be 7.0 × 105~1.3 × 106Ω-1m-1and the optical reflectivity value at 532 nm is about 0.55, which are typical values for true metal.
Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, P.O. Box 919-102, Mianyang 621900, Sichuan, P. R. China.|School of Science, Southwest University of Science and Technology, Mianyang, 610064, Sichuan, P. R. China.
Wei
W
Zhang
Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, P.O. Box 919-102, Mianyang 621900, Sichuan, P. R. China.
Zhiguo
Z
Li
Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, P.O. Box 919-102, Mianyang 621900, Sichuan, P. R. China.
Zhijian
Z
Fu
College of Science, National University of Defense Technology, Changsha, 410073, Hunan, P. R. China.
Jiayu
J
Dai
Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, P.O. Box 919-102, Mianyang 621900, Sichuan, P. R. China.
Qifeng
Q
Chen
School of Science, Southwest University of Science and Technology, Mianyang, 610064, Sichuan, P. R. China.
Lingcang
L
Cai