459 citations · 2.3k across the 63 of their papers we have counts for
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Temperature dependence of the charge density from first principles: application to the (222) forbidden reflection in silicon
Jean Paul Nery, Raveena Gupta, Olle Hellman +2
Forbidden reflections (FRs) in X-ray diffraction have inherently weak intensity and have long been studied, in particular in semiconductors like silicon. They serve as sensitive pr…
Theory of thermal expansion: Quasi-harmonic approximation and corrections from quasiparticle renormalization
Philip B. Allen
"Quasi-harmonic" (QH) theory should not be considered a low-order theory of anharmonic effects in crystals, but should be recognized as an important effect separate from "true" anh…
Quasiparticles and phonon satellites in spectral functions of semiconductors and insulators: Cumulants applied to full first principles theory and Fröhlich polaron
Jean Paul Nery, Philip B. Allen, Gabriel Antonius +3
The electron-phonon interaction causes thermal and zero-point motion shifts of electron quasiparticle (QP) energies . Other consequences of interactions, visible in angle-r…
Analysis of nonlocal phonon thermal conductivity simulations showing the ballistic to diffusive crossover
Philip B. Allen
Simulations (e.g. Zhou et al., Phys. Rev. B 79, 115201 (2009)) show nonlocal effects of the ballistic/diffusive crossover. The local temperature has nonlinear spatial variation not…
Low temperature-semiconductor band gap thermal shifts: T^4 shifts from ordinary acoustic and T^2 from piezoacoustic coupling
Philip B. Allen, Jean Paul Nery
At low temperature T, the experimental gap of silicon decreases as E_g(T)=E_g(0)-AT^4. The main reason is electron-phonon renormalization. The physics behind the T^4-power law is m…
First-principles study of pyroelectricity in GaN and ZnO
Jian Liu, Maria V. Fernández-Serra, Philip B. Allen
First-principles calculations are made for the primary pyroelectric coefficients of wurtzite GaN and ZnO. The pyroelectricity is attributed to the quasiharmonic thermal shifts of i…