Phys. Chem. Chem. Phys. [POMAM]

Abstract :

Spectral broadenings due to Dzyaloshinskii–Moriya interactions (DMI) were assessed with respect to the decoherence they induce through increased spin–spin interactions, as the role of DMI in developing magnetoelectric spin-chirality qubits is gaining recognition. The structurally related spin triangles [Fe₃O(PhCOO)₆(py)₃]ClO₄·py (Fe₃) and [Cr₃O(PhCOO)₆(py)₃]ClO₄·0.5py (Cr₃) were studied as frozen py-d₅ solutions with various pulsed Electron Paramagnetic Resonance (EPR) spectroscopy experiments, and under identical experimental conditions. Field-swept Hahn echo experiments revealed a match with continuous-wave (CW) spectra, while variable-temperature saturation/inversion recovery and Hahn echo decay experiments were used to extract the thermal evolutions of the spin–lattice relaxation and phase-memory times (T₁ and T_m, respectively). Nutation experiments revealed Rabi oscillations demonstrating that the spins of the complexes could be coherently manipulated. Careful comparisons of T_m times confirmed hyperfine interactions with the magnetic nuclei of the metal ions as an intrinsic source of decoherence. Comparisons of Rabi damping times revealed that DMI-induced spectral broadenings play a discernible but moderate role as an extrinsic source of decoherence for the nutation experiments and that they are not particularly detrimental to spin manipulations.

 

Graphical Abstract:

 

Reference :

Jérôme Robert, Nathalie Parizel, Philippe Turek and Athanassios K. Boudalis

Relevance of Dzyaloshinskii–Moriya spectral broadenings in promoting spin decoherence: a comparative pulsed-EPR study of two structurally related iron(III) and chromium(III) spin-triangle molecular qubits

Phys. Chem. Chem. Phys., 2019, 21, 19575-19584 - DOI : 10.1039/C9CP03422F

 

Contact chercheur :

Athanassios K. Boudalis (https://pomam.chimie.unistra.fr/aboudalis/), POMAM, Institut de Chimie (UMR 7177).