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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.
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Molecular Vibrational Polaritons Towards Quantum Technologies
Abstract Molecular vibrational polaritons (MVPs)—a hybrid molecular‐photon quasiparticle—and the development of a proof‐of‐principle quantum technology platform are discussed to simulate coherence transfer, for use at room temperature. It is shown that MVPs can form qubits, coherence, and have nonlinear interactions, all at room temperature. Some new insights, such as polaritonic nonlinearity dependence on macroscopic properties including cavity thickness and molecular concentrations are also uncovered. It is hoped that these advances can stimulate more research in developing this system into a quantum technology platform free from the constraints imposed by the requirement of cryogenic conditions.
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- Award ID(s):
- 1848215
- PAR ID:
- 10515713
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Quantum Technologies
- Volume:
- 5
- Issue:
- 8
- ISSN:
- 2511-9044
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/qute.202100163
