Ab Initio Electronic T₁ Spin Relaxation Times in Silicon and Diamond

Spin relaxation in inversion-symmetric crystals primarily occurs through the Elliott-Yafet mechanism, in which the injected spins are scattered by impurities at low temperatures and phonons at higher temperatures. We present an efficient first-principles approach for computing the phonon-limited Elliott-Yafet electronic spin relaxation time T₁ in materials ranging from metals to semiconductors and insulators. Our scheme combines fully-relativistic ab initio electron-phonon scattering with a novel approach to correctly treat Kramers degenerate electronic states. Application of our approach to silicon and diamond is discussed in this talk, where we analyze the temperature dependence of the spin relaxation times together with the contributions from intravalley and intervalley processes. The computed spin relaxation times in silicon are in excellent agreement with experiment above 50 K. Our work enables accurate ab initio calculations of the T₁ spin relaxation time in a range of materials, including topological ones, providing new microscopic insight into spin relaxation.