Room-temperature quantum sensing with photoexcited triplet electrons in organic crystals

Abstract

Quantum sensors have notably advanced high-sensitivity magnetic field detection. Here, we report quantum sensors constructed from polarized spin-triplet electrons in photoexcited organic chromophores, specifically focusing on pentacene-doped para-terphenyl ($\approx$0.1%). We demonstrate essential quantum sensing properties at room temperature: electronic optical polarization and state-dependent fluorescence contrast, by leveraging differential pumping and relaxation rates between triplet and ground states. We measure high optically detected magnetic resonance (ODMR) contrast $\approx 16.8\%$ of the triplet states at room temperature, along with long coherence times under spin echo and CPMG sequences, $T_2=2.7\mu$s and $T_2^{DD}=18.4\mu$s respectively, limited only by the triplet lifetimes. The material offers several advantages for quantum sensing, including the ability to grow large ($cm$-scale) crystals at low cost, the absence of paramagnetic impurities, and the diamagnetism of electronic states used for sensing when not optically illuminated. Utilizing pentacene as a representative of a broader class of spin triplet-polarizable organic molecules, this study highlights new potential for quantum sensing in chemical systems.

References in corpus (6)

• High-sensitivity diamond magnetometer with nanoscale resolution
• Magnetic field imaging with NV ensembles
• Realtime magnetic field sensing and imaging using a single spin in diamond
• Room-temperature optically detected coherent control of molecular spins
• Multi-photon multi-quantum transitions in the spin-3/2 silicon-vacancy centers of SiC
• Efficiently computing excitations of complex systems: linear-scaling time-dependent embedded mean-field theory in implicit solvent

Cited by in corpus (4)

• Chemically Tuning Room Temperature Pulsed Optically Detected Magnetic Resonance
• Experimental observation of a time rondeau crystal: Temporal Disorder in Spatiotemporal Order
• Organic molecules as single-photon sources
• Quantum sensing of time-dependent magnetic signals with molecular spins