Title | Quantum dynamics of nuclear spins and spin relaxation in organic semiconductors |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | Mkhitaryan, VV, Dobrovitski, VV |
Journal | Physical Review B |
Volume | 95 |
Pagination | ' |
Date Published | 06 |
Type of Article | Article |
ISBN Number | 2469-9950 |
Accession Number | WOS:000403069600002 |
Keywords | physics, spintronics, systems |
Abstract | We investigate the role of the nuclear-spin quantum dynamics in hyperfine-induced spin relaxation of hopping carriers in organic semiconductors. The fast-hopping regime, when the carrier spin does not rotate much between subsequent hops, is typical for organic semiconductors possessing long spin coherence times. We consider this regime and focus on a carrier random-walk diffusion in one dimension, where the effect of the nuclear-spin dynamics is expected to be the strongest. Exact numerical simulations of spin systems with up to 25 nuclear spins are performed using the Suzuki-Trotter decomposition of the evolution operator. Larger nuclear-spin systems are modeledutilizing the spin-coherent state P-representation approach developed earlier. We find that the nuclear-spin dynamics strongly influences the carrier spin relaxation at long times. If the random walk is restricted to a small area, it leads to the quenching of carrier spin polarization at a nonzero value at long times. If the random walk is unrestricted, the carrier spin polarization acquires a long-time tail, decaying as 1/root t. Based on the numerical results, we devise a simple formula describing the effect quantitatively. |
DOI | 10.1103/PhysRevB.95.214204 |
Custom 1 | Photonics |