Mechanism of Electron Spin Decoherence in a Partially Deuterated Glassy Matrix.

ABSTRACT: Long electron spin coherence lifetimes are essential for applications in quantum information science and electron paramagnetic resonance, for instance, for nanoscale distance measurements in biomolecular systems using double electron-electron resonance. We experimentally investigate the decoherence dynamics under the Hahn echo sequence of the organic radical d₁₈-TEMPO in a variably deuterated frozen water:glycerol matrix. The coherence time (phase memory time) T_M scales with proton concentration as [¹H]^-0.65. For selectively deuterated matrices, decoherence is accelerated in the presence of proton clustering, that is, substantial short-range density in the proton-proton radial distribution functions (<3 Å). Simulations using molecular dynamics and many-body spin quantum dynamics show excellent agreement with experiment and show that geminal proton pairs such as CH₂ and OH₂ groups are major decoherence drivers. This provides a predictive tool for designing molecular systems with long electron spin coherence times.

SUBMITTER: Jahn SM 

PROVIDER: S-EPMC9503049 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature