Room Temperature Electron Spin Coherence in Photogenerated Molecular Spin Qubit Candidates

One of the main challenges in the emerging field of molecularspintronicsis the identification of new spin qubit materials for quantum informationapplications. In this regard, recent work has shown that photoexcitedchromophore-radical systems are promising candidates to expandour repertoire of suitable candidate molecules. Here, we investigatea series of three chromophore-radical compounds composed ofa perylene diimide (PDI) chromophore and a stable 2,2,6,6-tetramethyl-piperidin-1-oxyl(TEMPO) radical by transient electron paramagnetic resonance (EPR)techniques. We explore the influence of isotope labeling of the TEMPOmoiety on the EPR spectra and electron spin coherence times of themolecular quartet states generated upon photoexcitation and illustratethat (i) a coherent manipulation of the spin state is possible inthese systems even at room temperature and that (ii) a spin coherencetime of 0.7 & mu;s can be achieved under these conditions. Thisdemonstration of electron spin coherence at ambient temperatures pavesthe way for practical applications of such systems in functional moleculardevices.

Automated summary

Recent research has found that photoexcited chromophore-radical systems have the potential to be new candidates for spin qubit materials, paving the way for practical applications in functional molecular devices.