Dynamical and anharmonic effects on the electron-phonon coupling and the zero-point renormalization of the electronic structure | |
Article | |
关键词: FUNCTIONAL PERTURBATION-THEORY; TEMPERATURE-DEPENDENCE; DIRECT-GAP; BAND-GAPS; SEMICONDUCTORS; DIAMOND; ISOTOPE; SILICON; SOLIDS; | |
DOI : 10.1103/PhysRevB.92.085137 | |
来源: SCIE |
【 摘 要 】
The renormalization of the band structure at zero temperature due to electron-phonon coupling is explored in diamond, BN, LiF, and MgO crystals. We implement a dynamical scheme to compute the frequency-dependent self-energy and the resulting quasiparticle electronic structure. Our calculations reveal the presence of a satellite band below the Fermi level of LiF and MgO. We show that the renormalization factor (Z), which is neglected in the adiabatic approximation, can reduce the zero-point renormalization (ZPR) by as much as 40%. Anharmonic effects in the renormalized eigenvalues at finite atomic displacements are explored with the frozen-phonon method. We use a nonperturbative expression for the ZPR, going beyond the Allen-Heine-Cardona theory. Our results indicate that high-order electron-phonon coupling terms contribute significantly to the zero-point renormalization for certain materials.
【 授权许可】
Free