Spin multifunctional transport properties of C₁₃ and C₁₄ molecule-based molecular nanodevices

Cyclocarbon molecules are promising candidates for molecular spintronics because they are newly synthesized carbon allotropes with excellent physical and chemical characteristics. Sun et al. (Nature, 2023, 623, 972-976) synthesized C₁₄ on an anthracene surface via tip-induced dehalogenation ring-opening reactions, demonstrating superior thermodynamic stability compared to C₁₈. Albrecht et al. (Science, 2024, 384, 677-682) utilized scanning probe microscopy tip manipulation to synthesize C₁₃in situ on decachlorofluorene, revealing a triplet ground state and a twisted geometric structure. This study utilizes first-principles calculations to explore the spin-multifunctional transport properties of nanodevices comprising C₁₃ and C₁₄ molecules that are connected in a coplanar manner to a zigzag-edged graphene nanoribbon. All considered devices exhibit spin filtering effects and rectification characteristics in parallel and antiparallel spin states. The spin filtering efficiency almost approaches 99% across the entire bias range, and the maximum rectification ratio exceeds 1 × 10⁴ for both C₁₃ and C₁₄ systems. Besides, the C₁₄ device displays considerable negative differential resistance, achieving a maximum peak-to-valley ratio of 5.71. Furthermore, modulating the temperature and thermal gradient of the nanoribbon electrodes enables thermal spin filtering, with thermal spin filtering efficiency in the parallel state approaching 99%. These findings provide theoretical guidance for designing multifunctional spin nanodevices based on cyclocarbon molecules, highlighting their potential as candidate materials for carbon-based device applications.