A unified ab initio theory of spin-phonon relaxation and decoherence uncovers fast dephasing in magnetic molecules.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41861011.
- Also identified by DOI 10.1126/sciadv.aeb3868 and PMC identifier 13004027.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Spin-phonon interactions are known to drive magnetic relaxation in solid-state systems but are generally overlooked as a contribution to spin decoherence through dephasing. Here, we extend quantum master equations to account for coherence terms and describe the full effect of up to two-phonon processes on spin dynamics. We implement this method fully ab initio for a molecule with large magnetization blocking temperature and show that, although strong axial magnetic anisotropy ensures slow magnetic relaxation approaching seconds at 77 kelvins, the superposition of Kramers doublets is coherent for less than 10 nanoseconds due to a two-phonon pure dephasing mechanism. This process, in principle, applies to any quantum system interacting with a thermal bath of phonons, advancing our understanding of quantum decoherence in solid-state systems.