The use of electric fields applied across magnetic heterojunctions that lack spatial inversion symmetry has been previously proposed as a nonmagnetic means of controlling localized magnetic moments through spin-orbit torques (SOT). The implementation of this concept at the single-molecule level has remained a challenge, however. Here, we present first-principles calculations of SOT in a single-molecule junction under bias and beyond linear response.
View Article and Find Full Text PDFMetal-metal contacts, though not yet widely realized, may provide exciting opportunities to serve as tunable and functional interfaces in single-molecule devices. One of the simplest components which might facilitate such binding interactions is the ferrocene group. Notably, direct bonds between the ferrocene iron center and metals such as Pd or Co have been demonstrated in molecular complexes comprising coordinating ligands attached to the cyclopentadienyl rings.
View Article and Find Full Text PDFThe method is widely used for calculating the electronic band structure of materials. The high computational cost of algorithms prohibits their application to many systems of interest. We present a periodic, low-scaling, and highly efficient algorithm that benefits from the locality of the Gaussian basis and the polarizability.
View Article and Find Full Text PDFWe report on the optical absorption characteristics of selectively positioned sulfur vacancies in monolayer MoS, as observed by photovoltage and photocurrent experiments in an atomistic vertical tunneling circuit at cryogenic and room temperature. Charge carriers are resonantly photoexcited within the defect states before they tunnel through an hBN tunneling barrier to a graphene-based drain contact. Both photovoltage and photocurrent characteristics confirm the optical absorption spectrum as derived from ab initio GW and Bethe-Salpeter equation approximations.
View Article and Find Full Text PDFAssociating atomic vacancies to excited-state transport phenomena in two-dimensional semiconductors demands a detailed understanding of the exciton transitions involved. We study the effect of such defects on the electronic and optical properties of WS-graphene and MoS-graphene van der Waals heterobilayers, employing many-body perturbation theory. We find that chalcogen defects and the graphene interface radically alter the optical properties of the transition-metal dichalcogenide in the heterobilayer, due to a combination of dielectric screening and the many-body nature of defect-induced intralayer and interlayer optical transitions.
View Article and Find Full Text PDF