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Title: Quantifying the effects of peripheral substituents on the spin-lattice relaxation of a vanadyl molecular quantum bit
Electron spin superpositions represent a critical component of emergent quantum technologies in computation, sensing, encryption, and communication. However, spin relaxation (T1) and decoherence (Tm) represent major obstacles to the implementation of molecular quantum bits (qubits). Synthetic strategies have made substantial progress in enhancing spin coherence times by minimizing contributions from surrounding electron and nuclear spins. For room-temperature operation, however, the lifetime of spin coherence becomes limited by coupling with vibrational modes of the lattice. Using pulse electron paramagnetic resonance (EPR) spectroscopy, we measure the spin-lattice relaxation of a vanadyl tetrapyrazinoporphyrazine complex appended with eight peripheral 2,6-diisopropylphenol groups (VOPyzPz-DIPP) and compare it to the relaxation of the archetypical vanadyl phthalocyanine molecular qubit (VOPc). The added peripheral groups lead to distinctly different spin relaxation behavior. While similar relaxation times are observed at low temperatures and ambient conditions, significant changes are observed for the orientation dependence of T1at 100 K, as well as the temperature dependence of T1over the intermediate temperature range spanning [Formula: see text]10–150 K. These results can be tentatively interpreted as arising from loosened spin-phonon coupling selection rules and a greater number of accessible acoustic and optical modes contributing to the spin relaxation behavior of VOPyzPz-DIPP relative to VOPc.  more » « less
Award ID(s):
2153081
PAR ID:
10592817
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
World Scientific
Date Published:
Journal Name:
Journal of Porphyrins and Phthalocyanines
Volume:
28
Issue:
06
ISSN:
1088-4246
Page Range / eLocation ID:
383 to 389
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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