IQIM Postdoctoral and Graduate Student Seminar

Jinsoo Park : "Ab initio electronic T1 spin relaxation times in silicon and diamond"

Abstract:

Spin relaxation in centrosymmetric crystals primarily occurs through the Elliott-Yafet mechanism, in which spin decoherence can be mediated by electron-phonon interactions. Predicting spin-phonon relaxation processes has mainly relied on empirical models, which are inadequate for quantitative prediction. In this talk, I will discuss our recently developed first-principles approach for computing the phonon-limited spin relaxation time, using the structure of the material as the only input. I will show our predicted spin relaxation times in two key materials for spintronic and quantum technologies, silicon and diamond.

Jin-Jian Zhou : "Computing charge transport in materials from first principles"

Abstract:

Calculations of charge transport, e.g. electric conductivity and carrier mobility, have relied on empirical approaches that lack predictive power and quantitative accuracy for the past several decades. Recent progress in combining density functional theory and related methods are enabling transport calculations in materials from first principles. A special role is played by the electron-phonon (e-ph) interactions, which typically dominate charge transport near room temperature. I will discuss our recently developed methods to compute e-ph scattering and charge transport, which use the structure of the material as the only input. I will also show how these developments enable accurate calculations of carrier mobility in polar semiconductors and perovskite oxides, leading to new insight into the conduction mechanisms in these materials.