Ab initio calculation of T2 using Lindbladian dynamics

A fundamental requirement for the development of spintronics are materials in which spin ensembles are sustained for sufficiently long length and time scales. The T1 time scale, and the corresponding spin-diffusion length scale, characterizes the decay of an initial spin polarization. However, when prepared in a superposition of energy eigenstates, the decay of the superposition is characterized by time scale T2, which can be much smaller than T1. The characterization of T2 in materials is crucial for the development of spin-qubit interconnects in addition to traditional spintronic applications. Using a recently-developed first-principles Lindbladian density-matrix simulation framework, we directly simulate Hahn spin echo measurements to extract T2 in exactly the same way as in experiments. We present the intrinsic, limiting T2 time scales accounting for spin-phonon relaxation for several materials spanning a wide range of dimensionality, anisotropy and symmetry, and compare them to the corresponding T1 spin relaxation time scales.