Spin multifunctional transport properties of C and C 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 (, 2023, , 972-976) synthesized C on an anthracene surface tip-induced dehalogenation ring-opening reactions, demonstrating superior thermodynamic stability compared to C. Albrecht (, 2024, , 677-682) utilized scanning probe microscopy tip manipulation to synthesize C 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 C and C 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 × 10 for both C and C systems. Besides, the C 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.