Spin-phonon relaxation in disparate materials from a universal ab initio density matrix approach
Junqing Xu, Adela Habib, Sushant Kumar, Feng Wu, Ravishankar Sundararaman, Yuan Ping
Received Date: 11th November 19
Designing new quantum materials with long-lived electron spin states is in urgent need of a general theoretical formalism and computational technique to reliably predict intrinsic spin relaxation times. We present a new, universal first-principles methodology based on Lindbladian dynamics of density matrices to calculate the spin-phonon relaxation time (\tau_s) of solids with arbitrary spin mixing and crystal symmetry. In particular, this method describes contributions of the Elliott-Yafet (EY) and D’yakonov-Perel’ (DP) mechanisms to spin relaxation, corresponding to systems with and without inversion symmetry, on an equal footing. Our ab initio predictions are in excellent agreement with experimental data for a broad range of materials. We found the temperature dependent \tau_s is directly proportional to carrier relaxation time for monolayer transition metal dichalcogenides (TMD), in contrast to the commonly-quoted inverse relationship in the DP mechanism. We disentangled spin and valley relaxation times and revealed their underlying mechanism that leads to long \tau_s of free carriers in TMD. This work underscores the predictive power of first-principles techniques for key physical properties to quantum information science.
Read in full at arXiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.