# Electron-phonon coupling and the metalization of solid helium at terapascal pressures

B. Monserrat, N. Drummond, C. Pickard, R. Needs

*Physical Review Letters* 112, 5 (2014)

#materials#highpressure#condensedmatter

Phase diagram of He at the pressure- temperature range relevant for cool WDs.

Solid He is studied in the pressure and temperature ranges 1–40 TPa and 0–10,000 K using first- principles methods. Anharmonic vibrational properties are calculated within a self-consistent field framework, including the internal and free energies, density-pressure relation, stress tensor, thermal expansion, and the electron-phonon coupling renormalization of the electronic band gap. We find that an accurate description of electron-phonon coupling requires us to use a non-perturbative approach. The metalization pressure of 32.9 TPa at 0 K is larger than found previously. The vibrational effects are large; for example at P = 30 TPa the band gap is increased by 2.8 eV by electron-phonon coupling and a further 0.1 eV by thermal expansion compared to the static value. The implications of the calculated metalization pressure for the cooling of white dwarfs are discussed.

#### Degree-correlations in a bursting dynamic network model

F. Vanni, P. Barucca

*Journal of Economic Interaction and Coordination*

#### Phase transition creates the geometry of the continuum from discrete space

R. Farr, T. Fink

*Physical Review E*

#### Intelligently chosen interventions have potential to outperform the diode bridge in power conditioning

F. Liu, Y. Zhang, O. Dahlsten, F. Wang

*Scientific Reports *

#### Portfolio analysis and geographical allocation of renewable sources: A stochastic approach

A. Scala, A. Facchini, U. Perna, R. Basosi

*Energy Policy*

#### Changes to Gate Closure and its impact on wholesale electricity prices: The case of the UK

A. Facchini, A. Rubino, G. Caldarelli, G. Liddo

*Energy Policy*

#### The statistical physics of real-world networks

G. Cimini, T. Squartini, F. Saracco, D. Garlaschelli, A. Gabrielli, G. Caldarelli

*Nature Reviews Physics*

#### PopRank: Ranking pages’ impact and users’ engagement on Facebook

A. Zaccaria, M. Vicario, W. Quattrociocchi, A. Scala, L. Pietronero

*PLoS ONE *

128 / 128 papers